fixup commit for tag 'distr2'

Removed one superfluous line.

Action

@@ -0,0 +1,135 @@
+name	"System definition"
+dir first
+action did_first
+failure "You have to run the shell script first in the directory first"
+fatal
+end
+name	"EM definition"
+dir etc
+end
+name "C preprocessor"
+dir util/cpp
+end
+name "EM definition library"
+dir util/data
+end
+name "Encode/Decode"
+dir util/misc
+end
+name "Shell files in bin"
+dir util/shf
+end
+name "EM assembler"
+dir util/ass
+end
+name "EM Peephole optimizer"
+dir util/opt
+end
+name "ACK archiver"
+dir util/arch
+end
+name "Program 'ack'"
+dir util/ack
+end
+name "Bootstrap for backend tables"
+dir util/cgg
+end
+name "LL(1) Parser generator"
+dir util/LLgen
+end
+name "Bootstrap for newest form of backend tables"
+dir util/ncgg
+end
+name "C frontend"
+dir lang/cem/comp
+end
+name "Basic frontend"
+dir lang/basic/src
+end
+name "Intel 8086 support"
+dir mach/i86
+indir
+end
+name "MSC6500 support"
+dir mach/6500
+indir
+end
+name "Motorola 6800 support"
+dir mach/6800
+indir
+end
+name "Motorola 6805 support"
+dir mach/6805
+indir
+end
+name "Motorola 6809 support"
+dir mach/6809
+indir
+end
+name "Intel 8080 support"
+dir mach/i80
+indir
+end
+name "2-2 Interpreter support"
+dir mach/int22
+indir
+end
+name "2-4 Interpreter support"
+dir mach/int24
+indir
+end
+name "4-4 Interpreter support"
+dir mach/int44
+indir
+end
+name "IBM PC/IX support"
+dir mach/ix
+indir
+end
+name "Motorola 68000 2-4 support"
+dir mach/m68k2
+indir
+end
+name "Motorola 68000 4-4 support"
+dir mach/m68k4
+indir
+end
+name "NS16032 support"
+dir mach/ns
+indir
+end
+name "PDP 11 support"
+dir mach/pdp
+indir
+end
+name "PMDS support"
+dir mach/pmds
+indir
+end
+name "PMDS 4/4 support"
+dir mach/pmds4
+indir
+end
+name "Signetics 2650 support"
+dir mach/s2650
+indir
+end
+name "Vax 2-4 support"
+dir mach/vax2
+indir
+end
+name "Vax 4-4 support"
+dir mach/vax4
+indir
+end
+name "Z80 support"
+dir mach/z80
+indir
+end
+name "Zilog Z8000 support"
+dir mach/z8000
+indir
+end
+name "Pascal frontend"
+dir lang/pc/pem
+end

DistrAction

@@ -0,0 +1 @@
+exec sh TakeAction distr distr/Action

Makefile

@@ -1,35 +0,0 @@
-cmp:           # compile everything and compare
-	(cd etc  ; make cmp )
-	(cd util ; make cmp )
-	(cd lang ; make cmp )
-	(cd mach ; make cmp )
-
-install:         # compile everything to machine code
-	(cd etc  ; make install )
-	(cd util ; make install )
-	(cd lang/cem ; make install )
-	(cd mach ; make install )
-	(cd lang/pc ; make install )
-
-clean:        # remove all non-sources, except boot-files
-	(cd doc ; make clean )
-	(cd man ; make clean )
-	(cd h   ; make clean )
-	(cd etc  ; make clean )
-	(cd util ; make clean )
-	(cd lang ; make clean )
-	(cd mach ; make clean )
-
-opr:            # print all sources
-	make pr | opr
-
-pr:             # print all sources
-	@( pr Makefile ; \
-	  (cd doc ; make pr ) ; \
-	  (cd man ; make pr ) ; \
-	  (cd h ; make pr ) ; \
-	  (cd etc  ; make pr ) ; \
-	  (cd lang ; make pr ) ; \
-	  (cd util ; make pr ) ; \
-	  (cd mach ; make pr ) \
-	)

NEW

@@ -0,0 +1,17 @@
+What's new:
+	A lot of things have changed since that previous distribution.
+It is not wise to mix files created by the previous version of the Kit
+with files belonging to this version, although that might sometimes work.
+The major additions are:
+	- Basic frontend
+	- New codegenerator
+	- LL(1) parser generator
+	- Vax backend with 4-byte wordsize
+	- Motorola 68000 backend with 4-byte wordsize
+	- Motorola 68000 interpreter for 2- and 4-byte wordsize
+	- Z8000 assembler and backend.
+	- 6805 assembler
+	- NatSem 16032 assembler
+	- Intel 8080 backend
+	- Zilog Z80 backend
+	- Signetics 2650 assembler

README

@@ -0,0 +1,2 @@
+Before starting installation you should read
+the file doc/install.pr

TakeAction

@@ -0,0 +1,109 @@
+case $# in
+0)	PAR=install ; CMD=Action ;;
+1)	PAR="$1" ; CMD=Action ;;
+2)	PAR="$1" ; CMD="$2" ;;
+*)	echo Syntax: "$0" [param [file]] ; exit 1 ;;
+esac
+if test -r "$CMD"
+then :
+else
+	case "$CMD" in
+	Action)		echo No Action file present ;;
+	*)		echo No Action file "($CMD)" present ;;
+	esac
+fi
+THISFILE=`pwd`/$0
+SYS=
+RETC=0
+{ while read LINE
+do
+	eval set $LINE
+	case x"$1" in
+	x#*)	;;
+	xname)		SYS="$2"
+			ACTION='make $PAR'
+			DIR=.
+			FM=no
+			FAIL='Failed for $SYS, see $DIR/Out'
+			SUCC='$SYS -- done'
+			ATYPE=
+			FATAL=no
+			DOIT=yes
+			;;
+	xfatal)		FATAL=yes ;;
+	xaction|xindir)	case x$ATYPE in
+			x)	ACTION=$2 ; ATYPE=$1
+				case $ATYPE$FM in
+				indirno) FAIL='Failed for $SYS' ;;
+				esac
+				;;
+			*)	echo Already specified an $ATYPE for this name
+				RETC=65 ;;
+			esac ;;
+	xfailure)	FM=yes 
+			FAIL="$2" ;;
+	xsuccess)	SUCC="$2" ;;
+	xdir)		DIR="$2" ;;
+	xsystem)	case `ack_sys` in
+			$2)	;;
+			*)	echo "Sorry, $SYS can only be made on $2 systems"
+				DOIT=no
+				;;
+			esac ;;
+	xend)		case $DOIT in
+			no)	continue ;;
+			esac
+			case x$SYS in
+			x)	echo Missing name line; RETC=65 ;;
+			*)	if test -d $DIR
+				then (
+				     cd $DIR
+				     X=
+				     case $ATYPE in
+				     indir)	
+					     if sh $THISFILE $PAR $ACTION
+					     then eval echo $SUCC
+					     else RETC=2 ; eval echo $FAIL
+					     fi ;;
+				     *)
+					     if eval "$ACTION >Out 2>&1 </dev/null"
+					     then eval echo $SUCC
+					     else RETC=1 ; X=: ; eval echo $FAIL
+					     fi
+					     ;;
+				     esac
+				     (echo ------- `pwd`
+				      cat Out
+				      $X rm -f Out
+				     ) 2>/dev/null 1>&- 1>&3
+				     exit $RETC
+				)
+				case $? in
+				0) ;;
+				*) case $RETC in
+				   0) RETC=$? ;;
+				   esac ;;
+				esac
+				else
+				      echo Directory $DIR for $SYS is inaccessible
+				      RETC=66
+				fi ;;
+			esac
+			case $FATAL$RETC in
+			yes0)	;;
+			yes*)	echo Fatal error, installation stopped.
+				exit $RETC ;;
+			esac
+			SYS=
+			;;
+	*)		echo Unknown keyword "$1"
+			RETC=67 ;;
+	esac
+done
+exit $RETC
+} <$CMD
+RETX=$?
+case $RETX in
+0)	exit $RETC ;;
+*)	exit $RETX ;;
+esac

bin/em.pascal

@@ -0,0 +1 @@
+exec /usr/em/doc/em.doc/int/em /usr/em/doc/em.doc/int/tables ${1-e.out} core

distr/Action

@@ -0,0 +1,15 @@
+name "Installation manual"
+dir doc
+end
+name "EM documentation"
+dir doc/em.doc
+end
+name "Pascal bootstrap files"
+dir lang/pc/pem
+end
+name "LLgen bootstrap files"
+dir util/LLgen
+end
+name "MSC6500 vend_library"
+dir mach/6500/libem
+end

distr/Action1

@@ -0,0 +1,6 @@
+name "vax2/cg bootstrap files"
+dir mach/vax2/cg
+end
+name "vax4/cg bootstrap files"
+dir mach/vax4/cg
+end

distr/Exceptions

@@ -0,0 +1,42 @@
+-- ./bin/em.pascal no RCS file
+-- ./doc/em.doc/doc.pr no RCS file
+-- ./doc/install.pr no RCS file
+-- ./h/em_mnem.h no RCS file
+-- ./h/em_pseu.h no RCS file
+-- ./h/em_spec.h no RCS file
+-- ./lang/basic/src/y.tab.c no RCS file
+-- ./lang/basic/src/y.tab.h no RCS file
+-- ./lang/pc/pem/pem22.m no RCS file
+-- ./lang/pc/pem/pem24.m no RCS file
+-- ./lib/LLgen/incl no RCS file
+-- ./lib/LLgen/rec no RCS file
+-- ./lib/ix/head_em no RCS file
+-- ./lib/ix/head_i no RCS file
+-- ./lib/ix/tail_em no RCS file
+-- ./lib/ix/tail_em.vend no RCS file
+-- ./lib/ix/tail_mon no RCS file
+-- ./mach/6500/libem/tail_em.ve.s.a no RCS file
+-- ./mach/vax2/cg/tables1.c no RCS file
+-- ./mach/vax2/cg/tables1.h no RCS file
+-- ./mach/vax4/cg/tables1.c no RCS file
+-- ./mach/vax4/cg/tables1.h no RCS file
+-- ./mach/z80/int/libpc/pc_tail.c.a no RCS file
+-- ./mkun/pubmac no distr2 yet
+-- ./mkun/tmac.q no distr2 yet
+-- ./mkun/tmac.q1 no distr2 yet
+-- ./mkun/tmac.q2 no distr2 yet
+-- ./mkun/tmac.q3 no distr2 yet
+-- ./mkun/tmac.q4 no distr2 yet
+-- ./mkun/tmac.q5 no distr2 yet
+-- ./mkun/tmac.q6 no distr2 yet
+-- ./mkun/tmac.q7 no distr2 yet
+-- ./mkun/tmac.q8 no distr2 yet
+-- ./util/LLgen/src/parser no RCS file
+-- ./util/LLgen/src/LLgen.c no RCS file
+-- ./util/LLgen/src/Lpars.c no RCS file
+-- ./util/LLgen/src/Lpars.h no RCS file
+-- ./util/LLgen/src/tokens.c no RCS file
+-- ./util/data/em_flag.c no RCS file
+-- ./util/data/em_mnem.c no RCS file
+-- ./util/data/em_pseu.c no RCS file
+-- ./util/data/em_ptyp.c no RCS file

distr/How_To

@@ -0,0 +1,74 @@
+How to make a fresh distribution:
+For a distribution you need ".distr" files and RCS files.
+The EM home directory contains a file called ".distr". It contains
+the names of all the files and directories you want to have in the distribution.
+The directories should contain .distr files, the other files should
+be placed under RCS.
+The current RCS revision name is "distr2".
+The are files that derive from other files and yet should be placed
+in the distribution.
+These files should not be placed under RCS.
+The file "Exceptions" in this directory contains the current list of
+these files.
+
+When all this is correct, use the shell script mktree the extract
+the distribution from the EM tree.
+	cd /usr/em ; sh distr/mktree destination_tree >distr/f.attf 2>&1
+Make sure that the destination tree exists and is empty!
+Failing to do that will almost certainly result in a welter of
+error messages.
+The file f.attf contains mktree error messages and should be compared
+to Exceptions.
+The actions of mktree are quite complicated. It starts in the current
+directory reading the ".distr" file, after copying that file to the
+destination tree.
+For each file mentioned there it performes certain actions:
+1- Directory	Change to that directory and call yourself recursively.
+2- File
+   a-           Try to do "co -rdistr2 destination_tree/path/destination_file"
+                on succes "chmod +w destination_file" 
+              else
+   b-           Try to do "co destination_tree/destination_file"
+                on succes "chmod +w destination_file" and
+                give message that says "Missing distr2 entry" (or some such). 
+              else
+   c-           I   Does a file LIST exist in this directory AND
+                    is the first line of LIST equal to the name of the
+                    destination file? If so, try to extract all the files
+                    named in the rest of the LIST file and call the program
+                    arch to create a library "arch cr `cat LIST`".
+                    In this manner libraries can be distributed whose members
+                    have their own RCS file! 
+              else
+                II  try to do "cp file destination_tree/path/destination_file"
+                    on succes give message that says "Missing RCS entry"
+                    (or some such). 
+              else
+   d-
+              give message that says "Missing entry" (or some such). 
+
+Now you have the tree but not everything is kosher yet.
+Some files derive from other files in the tree, those derivations should
+be done with the use of an already installed distribution.
+The files Action and Action1 in this directory contain the actions
+we now take. (Confession: most of the time we use /usr/em)
+One warning, to re-nroff the IR-81 report it takes more then just nroff
+because most nroff's can't stand that report and stop half-way.
+The ntroff program does the trick, but only on the 11's.
+	tbl sources | ntroff -Tlp | ntlp
+
+After running these re-derivation programs the distrubtion tree starts
+to look like the tree you need.
+There are too many files there though, especially the files created by
+the derivation process.
+That is why we now give the command:
+	dtar cdf distr2 .
+The file distr2 is the one you should put on tape!
+But,.... before doing that: Try it out!
+Repeat the process described in the installation manual.
+Only if that succeeds you are sure that you included the files needed,
+and gave all other files the correct "distr2" RCS id.
+After you sent the tape away, forbid ANYBODY to touch the distr2 id
+in your RCS files.
+					Good Luck,
+						Ed Keizer, 85/4/15.

distr/dwalk

@@ -0,0 +1,25 @@
+: ${CDIR=.}
+if test ! -r .distr
+then
+	echo ++ no .distr in $CDIR
+        exit 0
+fi
+${DS-:} $CDIR
+for i in `cat .distr`
+do
+        if test -d $i
+        then
+                ( if cd $i
+		  then 
+			${DD-:} $CDIR $i
+			CDIR=$CDIR/$i
+			export CDIR
+			exec /usr/em/distr/dwalk
+		  else
+			echo ++ Could not access $CDIR/$i
+		  fi
+		)
+	else
+		${DF-:} $CDIR $i
+        fi
+done

distr/echod

@@ -0,0 +1 @@
+echo $1/$2

distr/f.attf

@@ -0,0 +1,42 @@
+-- ./bin/em.pascal no RCS file
+-- ./doc/em.doc/doc.pr no RCS file
+-- ./doc/install.pr no RCS file
+-- ./h/em_mnem.h no RCS file
+-- ./h/em_pseu.h no RCS file
+-- ./h/em_spec.h no RCS file
+-- ./lang/basic/src/y.tab.c no RCS file
+-- ./lang/basic/src/y.tab.h no RCS file
+-- ./lang/pc/pem/pem22.m no RCS file
+-- ./lang/pc/pem/pem24.m no RCS file
+-- ./lib/LLgen/incl no RCS file
+-- ./lib/LLgen/rec no RCS file
+-- ./lib/ix/head_em no RCS file
+-- ./lib/ix/head_i no RCS file
+-- ./lib/ix/tail_em no RCS file
+-- ./lib/ix/tail_em.vend no RCS file
+-- ./lib/ix/tail_mon no RCS file
+-- ./mach/6500/libem/tail_em.ve.s.a no RCS file
+-- ./mach/vax2/cg/tables1.c no RCS file
+-- ./mach/vax2/cg/tables1.h no RCS file
+-- ./mach/vax4/cg/tables1.c no RCS file
+-- ./mach/vax4/cg/tables1.h no RCS file
+-- ./mach/z80/int/libpc/pc_tail.c.a no RCS file
+-- ./mkun/pubmac no distr2 yet
+-- ./mkun/tmac.q no distr2 yet
+-- ./mkun/tmac.q1 no distr2 yet
+-- ./mkun/tmac.q2 no distr2 yet
+-- ./mkun/tmac.q3 no distr2 yet
+-- ./mkun/tmac.q4 no distr2 yet
+-- ./mkun/tmac.q5 no distr2 yet
+-- ./mkun/tmac.q6 no distr2 yet
+-- ./mkun/tmac.q7 no distr2 yet
+-- ./mkun/tmac.q8 no distr2 yet
+-- ./util/LLgen/src/parser no RCS file
+-- ./util/LLgen/src/LLgen.c no RCS file
+-- ./util/LLgen/src/Lpars.c no RCS file
+-- ./util/LLgen/src/Lpars.h no RCS file
+-- ./util/LLgen/src/tokens.c no RCS file
+-- ./util/data/em_flag.c no RCS file
+-- ./util/data/em_mnem.c no RCS file
+-- ./util/data/em_pseu.c no RCS file
+-- ./util/data/em_ptyp.c no RCS file

distr/listall

@@ -0,0 +1,10 @@
+case $# in
+0)	DIR=. ;;
+1)	DIR=$1 ;;
+*)	echo $0 [directory] ; exit 1 ;;
+esac
+DD=`pwd`/listall.d
+DW=`pwd`/dwalk
+export DD
+cd $DIR
+$DW

distr/listall.d

@@ -0,0 +1,2 @@
+echo "<$1/$2>"
+ls -bCdx `cat .distr`

distr/listdirs

@@ -0,0 +1,10 @@
+case $# in
+0)	DIR=. ;;
+1)	DIR=$1 ;;
+*)	echo $0 [directory] ; exit 1 ;;
+esac
+DD=`pwd`/echod
+DW=`pwd`/dwalk
+export DD
+cd $DIR
+$DW

distr/mka

@@ -0,0 +1,9 @@
+set -e
+for i in `tail +2 $DESTDIR/$1/LIST`
+do
+	${DF-false} $1 $i
+done
+cd $DESTDIR/$1
+arch cr `cat LIST`
+: I do not remove the files constituating the library, because
+: they might be present in .distr

distr/mkd

@@ -0,0 +1 @@
+mkdir $DESTDIR/$1/$2

distr/mkf

@@ -0,0 +1,23 @@
+if co -q -rdistr2 $DESTDIR/$1/$2 >/dev/null 2>&1
+then
+	chmod +w $DESTDIR/$1/$2
+elif co -q $DESTDIR/$1/$2 >/dev/null 2>&1
+then
+	chmod +w $DESTDIR/$1/$2
+	echo -- $1/$2 no distr2 yet
+elif grep LIST .distr >/dev/null 2>&1 &&
+     (test "$2" = "`head -1 $DESTDIR/$1/LIST`") >/dev/null 2>&1 &&
+     ${DA-false} "$1" "$2"
+then
+:	Fetched library contents one by one and put them together
+elif cp $2 $DESTDIR/$1/$2 >/dev/null 2>&1
+then
+	echo -- $1/$2 no RCS file
+else
+	echo ++ $1/$2 not present
+fi
+case $2 in
+LIST)	if (test -r $DESTDIR/$1/`head -1 $DESTDIR/$1/LIST`) >/dev/null 2>&1
+	then echo ++ LIST files must be in .distr before their libraries!!!
+	fi ;;
+esac

distr/mks

@@ -0,0 +1 @@
+cp .distr $DESTDIR/$1

distr/mktree

@@ -0,0 +1,15 @@
+case $# in
+1)	;;
+*)	echo $0 directory ; exit 1 ;;
+esac
+DDIR=/usr/em/distr
+case $1 in
+/*)	DESTDIR=$1 ;;
+*)	DESTDIR=`pwd`/$1 ;;
+esac
+DS=$DDIR/mks
+DD=$DDIR/mkd
+DF=$DDIR/mkf
+DA=$DDIR/mka
+export DESTDIR DS DD DF DA
+$DDIR/dwalk

distr/todistr

@@ -0,0 +1,26 @@
+REV=
+FILE=
+while :
+do
+	case $# in
+	0)	break ;;
+	esac
+	ARG="$1"
+	shift
+	case "$ARG" in
+	-r*)	REV=`echo "$ARG"| sed s/-r//` ;;
+	-*)	FLAGS="$FLAGS $ARG" ;;
+	*)	case x$FILE in
+		x)	FILE="$ARG" ;;
+		*)	echo todistr can only be done on one file at the time
+			exit 1 ;;
+		esac
+	esac
+done
+case x$REV in
+x)	REV=`rlog -h "$FILE"|sed -n -e '/head/s/^head:[ 	]*//p'` ;;
+esac
+case x$REV in
+x)	exit 2 ;;
+esac
+rcs -ndistr2:$REV $FLAGS $FILE

distr/ts

@@ -0,0 +1,2 @@
+DD=`pwd`/ts
+echo OK

doc/Makefile

@@ -1,7 +1,10 @@
+# $Header$
+
 SUF=pr
 PRINT=cat
 RESFILES=cref.$(SUF) pcref.$(SUF) val.$(SUF) v7bugs.$(SUF) install.$(SUF)\
-ack.$(SUF) cg.$(SUF) regadd.$(SUF) peep.$(SUF) toolkit.$(SUF)
+ack.$(SUF) cg.$(SUF) regadd.$(SUF) peep.$(SUF) toolkit.$(SUF) LLgen.$(SUF)\
+basic.$(SUF) 6500.$(SUF) ncg.$(SUF)
 NROFF=nroff
 MS=-ms
 
@@ -13,21 +16,31 @@ ack.$(SUF):         ack.doc
 		$(NROFF) $(MS) $? >$@
 cg.$(SUF):		cg.doc
 		$(NROFF) $(MS) $? >$@
+ncg.$(SUF):		ncg.doc
+		$(NROFF) $(MS) $? >$@
 regadd.$(SUF):		regadd.doc
 		$(NROFF) $(MS) $? >$@
 install.$(SUF):     install.doc
 		$(NROFF) $(MS) $? >$@
 pcref.$(SUF):       pcref.doc
 		$(NROFF) $? >$@
+basic.$(SUF):       basic.doc
+		$(NROFF) $(MS) $? >$@
 peep.$(SUF):	peep.doc
 		$(NROFF) $(MS) $? >$@
 val.$(SUF):         val.doc
 		$(NROFF) $? >$@
 toolkit.$(SUF):	toolkit.doc
 		$(NROFF) $(MS) $? >$@
+LLgen.$(SUF):	LLgen.doc
+		eqn $? | $(NROFF) $(MS) >$@
+6500.$(SUF):	6500.doc
+		$(NROFF) $(MS) $? >$@
 
 install cmp:
 
+distr:		install.doc
+		nroff -Tlp install.doc >install.pr
 pr:
 		@make "SUF="$SUF "NROFF="$NROFF "PRINT="$PRINT $(RESFILES) \
 			>make.pr.out 2>&1

doc/ack.doc

@@ -1,3 +1,4 @@
+.\" $Header$
 .nr LL 7.5i
 .tr ~
 .nr PD 1v

doc/basic.doc

@@ -0,0 +1,849 @@
+.\" $Header$
+.TL
+.de Sy
+.LP
+.IP \fBsyntax\fR 10
+..
+.de PU
+.IP \fBpurpose\fR 10
+..
+.de RM
+.IP \fBremarks\fR 10
+..
+The ABC compiler
+.AU
+Martin L. Kersten
+.AI
+Department of Mathematics and Computer Science.
+.br
+Vrije Universiteit
+.AB
+This manual describes the 
+programming language BASIC and its compiler
+included in the Amsterdam Compiler Kit.
+.AE
+.SH
+INTRODUCTION.
+.LP
+The BASIC-EM compiler is an extensive implementation of the
+programming language BASIC.
+The language structure and semantics are modelled after the 
+BASIC interpreter/compiler of Microsoft (tr), a detailed comparison
+is provided in appendix A.
+.LP
+The compiler generates code for a virtual machine, the EM machine
+[[ACM, etc]]
+Using EM as an intermediate machine results in a highly portable
+compiler and BASIC code.
+The drawback of EM is that it does not directly reflect one particular
+hardware design, which means that many of 
+the low level operations available within 
+BASIC are ill-defined or even inapplicable.
+To mention a few, the peek and poke instructions are likely
+to be behave errorneous, while line printer and tapedeck 
+primitives are unknown.
+.LP
+This manual is divided into three chapters.
+The first chapter discusses the general language syntax and semantics.
+Chapter two describes the statements available in BASIC-EM.
+Chapter 3 describes the predefined functions,
+ordered alphabetically.
+Appendix A discusses the differences with
+Microsoft BASIC. Appendix B describes all reserved symbols.
+Appendix C lists the error messages in use.
+.SH
+SYNTAX NOTATION
+.LP
+The conventions for syntax presentation are as follows:
+.IP CAPS 10
+Items are reserved words, must be input as shown
+.IP <> 10
+Items in lowercase letters enclosed in angular brackets
+are to be supplied by the user.
+.IP [] 10
+Items are optional.
+.IP \.\.\. 10
+Items may be repeated any number of times 
+.IP {} 10
+A choice between two or more alternatives. At least one of the entries
+must be chosen.
+.IP | 10
+Vertical bars separate the choices within braces.
+.LP
+All punctuation must be included where shown.
+.NH 1
+GENERAL INFORMATION
+.LP
+The BASIC-EM compiler is designed for a UNIX based environment.
+It accepts a text file with your BASIC program (suffix .b) and generates
+an executable file, called a.out.
+.NH 2
+LINE FORMAT
+.LP
+A BASIC program consists of a series of lines, starting with a 
+positive line number in the range 0 to 65529.
+A line may consists of more then one physical line on your terminal, but must
+is limited to 1024 characters.
+Multiple BASIC statements may be placed on a single line, provided
+they are separated by a colon (:).
+.NH 2
+CONSTANTS
+.LP
+The BASIC compiler character set is comprised of alphabetic
+characters, numeric characters, and special characters shown below.
+.DS
+= + - * / ^ ( ) % # $ \\ _
+! [ ] , . ; : & ' ? > <  \\ (blanc)
+.DE
+.LP
+BASIC uses two different types of constants during processing:
+numeric and string constants.
+.br
+A string constant is a sequence of characters taken from the ASCII
+character set enclosed by double quotation marks.
+.br
+Numeric constants are positive or negative numbers, grouped into
+five different classes.
+.IP "a) integer constants" 25
+Whole numbers in the range of -32768 and 32767. Integer constants do
+not contain decimal points.
+.IP "b) fixed point constants" 25
+Positive or negative real numbers, i.e. numbers with a decimal point.
+.IP "c) floating point constants" 25
+Real numbers in scientific notation. A floating point constant
+consists of an optional signed integer or fixed point number
+followed by the letter E (or D) and an optional signed integer
+(the exponent).
+The allowable range of floating point constants is 10^-38 to 10^+38.
+.IP "d) Hex constants" 25
+Hexadecimal numbers, denoted by the prefix &H.
+.IP "d) Octal constants" 25
+Octal numbers, denoted by the prefix &O.
+.NH 2
+VARIABLES
+.LP
+Variables are names used to represent values in a BASIC program.
+A variable is assigned a value by assigment specified in the program.
+Before a variable is assigned its value is assumed to be zero.
+.br
+Variable names are composed of letters, digits or the decimal point,
+starting with a letter. Up to 40 characters are significant.
+A variable name be be followed by any of the following  type 
+declaration characters:
+.IP % 5
+Defines an integer variable
+.IP ! 5
+Defines a single precision variable (see below)
+.IP # 5
+Defines a double precision variable
+.IP $ 5
+Defines a string variable.
+.LP
+NOTE: Two variables with the same name but different type is
+considered illegal.
+.LP
+Beside single valued variables, values may be grouped
+into tables or arrays.
+Each element in an array is referenced by the array name and an index,
+such a variable is called a subscripted variable.
+An array has as many subscripts as there are dimensions in the array,
+the maximum of which is 11.
+.br
+If a variable starts with FN it is assumed to be a call to a user defined
+function. 
+.br
+A variable name may not be a reserved word nor the name 
+of a predefined function.
+A list of all reserved identifiers is included as Appendix ?.
+.NH 2
+EXPRESSIONS
+.LP
+BASIC-EM differs from Microsoft BASIC in supporting floats in one precision
+only (due to EM).
+All floating point constants have the same precision, i.e. 16 digits.
+.LP
+When necessary the compiler will convert a numeric value from
+one type to another.
+A value is always converted to the precision of the variable it is assigned
+to.
+When a floating point value is converted to an integer the fractional
+portion is rounded.
+In an expression all values are converted to the same degree of precision,
+i.e. that of the most precise operand.
+.br
+Division by zero results in the message "Division by zero".
+If overflow (or underflow) occurs, the "Overflow (underflow)" message is
+displayed and  execution is terminated (contrary to Microsoft).
+.SH
+Arithmetic
+.LP
+The arithmetic operators in order of precedence,a re:
+.DS L
+\^		Exponentiation
+-		Negation
+*,/,\\,MOD	Multiplication, Division, Remainder
++,-		Addition, Substraction
+.DE
+The operator \\\\ denotes integer division, its operands are rounded to
+integers before the operator is applied.
+Modulus arithmetic is denoted by the operator MOD, which yields the
+integer value that is the remainder of an integer division.
+.br
+The order in which operators are performed can be changec with parentheses.
+.SH
+Relational
+.LP
+The relational operators in order of precedence, are:
+.DS
+=	Equality
+<>	Inequality
+<	Less than
+>	Greater than
+<=	Less than or equal to
+>=	Greater than or equal to
+.DE
+The relational operators are used to compare two values and returns
+either "true" (-1) or "false" (0) (See IF statement).
+The precedence of the relational operators is lower 
+then the arithmetic operators.
+.SH
+Logical
+.LP
+The logical operators performs tests on multiple relations, bit manipulations,
+or Boolean operations.
+The logical operators returns a bitwise result ("true" or "false").
+In an expression, logical operators are performed after the relational and
+arithmetic operators.
+The logical operators work by converting their operands to signed
+two-complement integers in the range -32768 to 32767.
+.DS
+NOT		Bitwise negation
+AND		Bitwise and
+OR		Bitwise or
+XOR		Bitwise exclusive or
+EQV		Bitwise equivalence
+IMP		Bitwise implies
+.DE
+.SH
+Functional
+.LP
+A function is used in  an expression to call a system or user defined
+function.
+A list of predefined functions is presented in chapter 3.
+.SH
+String operations
+.LP
+Strings can be concatenated by using +. Strings can be compared with
+the relational operators. String comparison is performed in lexicographic
+order.
+.NH 2
+ERROR MESSAGES
+.LP
+The occurence of an error results in termination of the program
+unless an ON....ERROR statement has been encountered.
+.NH 1
+B-EM STATEMENTS
+.LP
+This chapter describes the statements available within the BASIC-EM
+compiler. Each description is formatted as follows:
+.Sy
+Shows the correct syntax for the statement. See introduction of
+syntax notation above.
+.PU
+Describes the purpose and details of the instructions.
+.RM
+Describes special cases, deviation from Microsoft BASIC etc.
+.LP
+.NH 2 
+CALL
+.Sy
+CALL <variable name>[(<argument list>)]
+.PU
+The CALL statement provides the means to execute procedures
+and functions written in another language included in the
+Amsterdam Compiler Kit.
+The argument list consist of (subscripted) variables.
+The BASIC compiler pushes the address of the arguments on the stack in order
+of encounter.
+.RM
+Not yet available
+.NH 2
+CLOSE
+.Sy
+CLOSE [[#]<file number>[,[#]<file number...>]]
+.PU
+To terminate I/O on a disk file.
+<file number> is the number associated with the file 
+when it was OPENed (See OPEN). Ommission of parameters results in closing
+all files.
+.sp
+The END statement and STOP statement always issue a CLOSE of
+all files.
+.NH 2
+DATA
+.Sy
+DATA <list of constants>
+.PU
+DATA statements are used to construct a data bank of values that are
+accessed by the program's READ statement.
+DATA statements are non-executable,
+the data items are assembled in a data file by the BASIC compiler.
+This file can be replaced, provided the layout remains
+the same (otherwise the RESTORE won't function properly).
+.sp
+The list of data items consists of numeric and string constants
+as discussed in section 1.
+Moreover, string constants starting with a letter and not
+containing blancs, newlines, commas, colon need not be enclosed with
+the string quotes.
+.sp
+DATA statements can be reread using the RESTORE statement.
+.NH 2
+DEF FN
+.Sy
+DEF FN<name> [(<parameterlist>)]=<expression>
+.PU
+To define and name a function that is written by the user.
+<name> must be an identifier and should be preceded by FN,
+which is considered integral part of the function name. 
+<expression> defines the expression to be evaluated upon function call.
+.sp
+The parameter list is comprised of a comma separated 
+list of variable names, used within the function definition,
+that are to replaced by values upon function call.
+The variable names defined in the parameterlist, called formal
+parameters, do not affect the definition and use of variables
+defined with the same name in the rest of the BASIC program.
+.sp
+A type declaration character may be suffixed to the function name to
+designate the data type of the function result.
+.NH 2
+DEFINT/SNG/DBL/STR
+.Sy
+DEF<type> <range of letters>
+.PU
+Any undefined variable starting with the letter included in the range of
+letters is declared of type <type> unless a type declaration character
+is appended.
+The range of letters is a comma separated list of characters and
+character ranges (<letter>-<letter>).
+.NH 2
+DIM
+.Sy
+DIM <list of subscripted variable>
+.PU
+The DIM statement allocates storage for subscripted variables.
+If an undefined subscripted variable is used 
+the maximum value of the array subscript(s) is assumed to be 10.
+A subscript out of range is signalled by the program (when RCK works)
+The minimum subscript value is 0, unless the OPTION BASE statement has been
+encountered.
+.sp
+All variables in a subscripted variable are initially zero.
+.sp
+BUG. Multi-dimensional arrays MUST be defined.
+.NH 2
+END
+.Sy
+END
+.PU
+END terminates a BASIC program and returns to the UNIX shell.
+An END statement at the end of the BASIC program is optional.
+.NH 2
+ERR and ERL
+.PU
+Whenever an error occurs the variable ERR contains the
+error number and ERL the BASIC line where the error occurred.
+The variables are usually used in error handling routines
+provided by the user.
+.NH 2
+ERROR
+.Sy
+ERROR <integer expression>
+.PU
+To simulate the occurrence of a BASIC error.
+To define your own error code use a value not already in
+use by the BASIC runtime system.
+The list of error messages currently in use 
+can be found in appendix B.
+.NH 2
+FIELD
+.PU
+To be implemented.
+.NH 2
+FOR...NEXT
+.Sy
+FOR <variable>= <low>TO<high>[STEP<size>]
+.br
+ ......
+.br
+NEXT [<variable>][,<variable>...]
+.PU
+The FOR statements allows a series of statements to be performed
+repeatedly. <variable> is used as a counter. During the first
+execution pass it is assigned the value <low>,
+an arithmetic expression. After each pass the counter
+is incremented with the step size <size>, an expression.
+Ommission of the step size is intepreted as an increment of 1.
+Execution of the program lines specified between the FOR and the NEXT
+statement is terminated as soon as <low> is greater than <high>
+.sp
+The NEXT statement is labeled with the name(s) of the counter to be
+incremented.
+.sp
+The body of the FOR statement is skipped when the initial value of the
+loop times the sign of the step exceeds the value of the highest value
+times the sign of the step.
+.sp
+The variables mentioned in the NEXT statement may be ommitted, in which case
+the variable of increment the counter of the most recent FOR statement.
+If a NEXT statement is encountered before its corresponding FOR statement,
+the error message "NEXT without FOR" is generated.
+.NH 2
+GET
+.Sy
+GET [#]<file number>[, <record number>]
+.PU
+To be implemented.
+.NH 2
+GOSUB...RETURN
+.Sy
+GOSUB <line number
+  ...
+.br
+RETURN
+.PU
+The GOSUB statement branches to the first statement of a subroutine.
+The RETURN statement cause a branch back to the statement following the
+most recent GOSUB statement.
+A subroutine may contain more than one RETURN statement.
+.sp
+Subroutines may be called recursively. 
+Nesting of subroutine calls is limited, upon exceeding the maximum depth
+the error message "XXXXX" is displayed.
+.NH 2
+GOTO
+.Sy
+GOTO <line number>
+.PU
+To branch unconditionally to a specified line in the program.
+If <line number> does not exists, the compilation error message
+"Line not defined" is displayed.
+.RM
+Microsoft BASIC continues at the first line
+equal or greater then the line specified.
+.NH 2
+IF...THEN
+.Sy
+.br
+IF <expression> THEN {<statements>|<line number>}
+[ELSE {<statements>|<line number>}]
+.br
+.Sy
+IF <expression> GOTO <line number>
+[ELSE {<statements>|<line number>}]
+.PU
+The IF statement is used
+to make a decision regarding the program flow based on the
+result of the expressions.
+If the expression is not zero, the THEN or GOTO clause is
+executed. If the result of <expression> is zero, the THEN or
+GOTO clause is ignored and the ELSE clause, if present is
+executed.
+.br
+IF..THEN..ELSE statements may be nested.
+Nesting is limited by the length of the line.
+The ELSE clause matches with the closests unmatched THEN.
+.sp
+When using IF to test equality for a value that is the
+result of a floating point expression, remember that the
+internal representation of the value may not be exact.
+Therefore, the test should be against a range to
+handle the relative error.
+.RM
+Microsoft BASIC allows a comma before THEN.
+.NH 2
+INPUT
+.Sy
+INPUT [;][<"prompt string">;]<list of variables>
+.PU
+An INPUT statement can be used to obtain values from the user at the
+terminal.
+When an INPUT statement is encountered a question mark is printed
+to indicate the program is awaiting data.
+IF <"prompt string"> is included, the string is printed before the
+the question mark. The question mark is suppressed when the prompt
+string is followed by a comma, rather then a semicolon.
+.sp
+For each variable in the variable a list a value should be supplied.
+Data items presented should be separated by a comma.
+.sp
+The type of the variable in the variable list must aggree with the
+type of the data item entered. Responding with too few or too many
+data items causes the message "?Redo". No assignment of input values
+is made until an acceptable response is given.
+.RM
+The option to disgard the carriage return with the semicolon after the
+input symbol is not yet implemented.
+.NH 2
+INPUT [#]
+.Sy
+INPUT #<file number>,<list of variables>
+.PU
+The purpose of the INPUT# statement is to read data items from a sequential
+file and assign them to program variables.
+<file number> is the number used to open the file for input.
+The variables mentioned are (subscripted) variables.
+The type of the data items read should aggree with the type of the variables.
+A type mismatch results in the error message "XXXXX".
+.sp
+The data items on the sequential file are separated by commas and newlines.
+In scanning the file, leading spaces, new lines, tabs, and
+carriage returns are ignored. The first character encountered 
+is assumed to be the state of a new item.
+String items need not be enclosed with double quotes, provided
+it does not contain spaces, tabs, newlines and commas,
+.RM
+Microsoft BASIC won't assign values until the end of input statement.
+This means that the user has to supply all the information.
+.NH 2
+LET
+.Sy
+[LET]<variable>=<expression>
+.PU
+To assign  the value of an expression to a (subscribted) variable.
+The type convertions as dictated in section 1.X apply.
+.NH 2
+LINE INPUT
+.Sy
+LINE INPUT [;][<"prompt string">;]<string variable>
+.PU
+An entire line of input is assigned to the string variable.
+See INPUT for the meaning of the <"prompt string"> option.
+.NH 2
+LINE INPUT [#]
+.Sy
+LINE INPUT #<file number>,<string variable>
+.PU
+Read an entire line of text from a sequential file <file number>
+and assign it to a string variable.
+.NH 2
+LSET and RSET
+.PU
+To be implemented
+.NH 2
+MID$
+.Sy
+MID$(<string expr1>,n[,m])=<string expr2>
+.PU
+To replace a portion of a string with another string value.
+The characters of <string expr2> replaces characters in <string expr1>
+starting at position n. If m is present, at most m characters are copied,
+otherwise all characters are copied.
+However, the string obtained never exceeds the length of string expr1.
+.NH 2
+ON ERROR GOTO
+.Sy
+ON ERROR GOTO <line number>
+.PU
+To enable error handling within the BASIC program.
+An error may result from arithmetic errors, disk problems, interrupts, or
+as a result of the ERROR statement.
+After printing an error message the program is continued at the
+statements associated with <line number>.
+.sp
+Error handling is disabled using ON ERROR GOTO 0.
+Subsequent errors result in an error message and program termination.
+.NH 2
+ON...GOSUB and ON ...GOTO
+.Sy
+ON <expression> GOSUB <list of line numbers>
+ON <expression> GOTO <list of line numbers>
+.PU
+To branch to one of several specified line numbers or subroutines, based
+on the result of the <expression>. The list of line numbers are considered
+the first, second, etc alternative. Branching to the first occurs when
+the expression evaluates to one, to the second alternative on two, etc.
+If the value of the expression in zero or greater than the number of alternatives, processing continues at the first statement following the ON..GOTO 
+(ON GOSUB) statement.
+When the expression results in a negative number the 
+an "Illegal function call" error occurs.
+.NH 2
+OPEN
+.NH 2
+OPTION BASE
+.Sy
+OPTION BASE n
+.PU
+To declare the lower bound of subsequent array subscripts as either
+0 or 1. The default lower bound is zero.
+.NH 2
+POKE
+.Sy
+POKE <expr1>,<expr2>
+.PU
+To poke around in memory. The use of this statement is not recommended,
+because it requires full understanding of both
+the implementation of the Amsterdam
+Compiler Kit and the hardware characteristics.
+.NH 2
+PRINT [USING]
+.NH 2
+PUT
+.PU
+To be implemented
+.NH 2
+RANDOMIZE
+.Sy
+RANDOMIZE [<expression>]
+.PU
+To reset the random seed. When the expression is ommitted, the system
+will ask for a value between -32768 and 32767.
+The random number generator returns the same sequence of values provided
+the same seed is used.
+.NH 2
+READ
+.Sy
+READ <list of variables>
+.PU
+To read values from the DATA statements and assign them to variables.
+The type of the variables should match to the type of the items being read,
+otherwise a "Syntax error" occurs.
+.NH 2
+REM
+.Sy
+REM <remark>
+.PU
+To include explantory information in a program.
+The REM statements are not executed.
+A single quote has the same effect as  : REM, which
+allows for the inclusion of comment at the end of the line.
+.RM
+Microsoft BASIC does not allow REM statements as part of
+DATA lines.
+.NH 2
+RESTORE
+.Sy
+RESTORE  [<line number>]
+.PU
+To allow DATA statements to be re-read from a specific line.
+After a RESTORE statement is executed, the next READ accesses
+the first item of the DATA statements.
+If <line number> is specified, the next READ accesses the first
+item in the specified line.
+.sp
+Note that data statements result in a sequential datafile generated
+by the compiler, being read by the read statements.
+This data file may be replaced using the operating system functions
+with a modified version, provided the same layout of items
+(same number of lines and items per line) is used.
+.NH 2
+STOP
+.Sy
+STOP
+.PU
+To terminate the execution of a program and return to the operating system
+command interpreter. A STOP statement results in the message "Break in line
+???"
+.NH 2
+SWAP
+.Sy
+SWAP <variable>,<variable>
+.PU
+To exchange the values of two variables.
+.NH 2
+TRON/TROFF
+.Sy
+TRON
+.Sy
+TROFF
+.PU
+As an aid in debugging the TRON statement results in a program
+listing each line being interpreted. TROFF disables generation of
+this code.
+.NH 2
+WHILE...WEND
+.Sy
+WHILE <expression>
+  .....
+WEND
+.PU
+To execute a series of BASIC statements as long as a conditional expression
+is true. WHILE...WEND loops may be nested.
+.NH 2
+WRITE 
+.Sy
+WRITE [<list of expressions>]
+.PU
+To write data at the terminal in DATA statement layout conventions.
+The expressions should be separated by commas.
+.NH 2
+WRITE #
+.Sy
+WRITE #<file number> ,<list of expressions>
+.PU
+To write a sequential data file, being opened with the "O" mode.
+The values are being writting using the DATA statements layout conventions.
+.NH
+FUNCTIONS
+.LP
+.IP ABS(X) 12
+Returns the absolute value of expression X
+.IP ASC(X$) 12
+Returns the numeric value of the first character of the string.
+If X$ is not initialized an "Illegal function call" error
+is returned.
+.IP ATN(X) 12
+Returns the arctangent of X in radians. Result is in the range
+of -pi/2 to pi/2.
+.IP CDBL(X) 12
+Converts X to a double precision number.
+.IP CHR$(X) 12
+Converts the integer value X to its ASCII character. 
+X must be in the range of 0 to 127.
+It is used for cursor addressing and generating bel signals.
+.IP CINT(X) 12
+Converts X to an integer by rounding the fractional portion.
+If X is not in the range -32768 to 32767 an "Overflow"
+error occurs.
+.IP COS(X) 12
+Returns the cosine of X in radians.
+.IP CSNG(X) 12
+Converts X to a double precision number.
+.IP CVI(<2-bytes>) 12
+Convert two byte string value to integer number.
+.IP CVS(<4-bytes>) 12
+Convert four byte string value to single precision number.
+.IP CVD(<8-bytes>) 12
+Convert eight byte string value to double precision number.
+.IP EOF[(<file-number>)] 12
+Returns -1 (true) if the end of a sequential file has been reached.
+.IP EXP(X) 12
+Returns e(base of natural logarithm) to the power of X.
+X should be less then 10000.0.
+.IP FIX(X) 12
+Returns the truncated integer part of X. FIX(X) is
+equivalent to SGN(X)*INT(ABS(X)).
+The major difference between FIX and INT is that FIX does not
+return the next lower number for negative X.
+.IP HEX$(X) 12
+Returns the string which represents the hexadecimal value of
+the decimal argument. X is rounded to an integer using CINT
+before HEX$ is evaluated.
+.IP INT(X) 12
+Returns the largest integer <= X.
+.IP INPUT$(X[,[#]Y]) 12
+Returns the string of X characters read from the terminal or
+the designated file.
+.IP LEX(X$) 12
+Returns the number of characters in the string X$.
+Non printable and blancs are counted too.
+.IP LOC(<file\ number>) 12
+For sequential files LOC returns 
+position of the read/write head, counted in number of bytes.
+For random files the function returns the record number just
+read or written from a GET or PUT statement.
+If nothing was read or written 0 is returned.
+.IP LOG(X) 12
+Returns the natural logarithm of X. X must be greater than zero.
+.IP MID$(X,I,[J]) 12
+To be implemented.
+.IP MKI$(X) 12
+Converts an integer expression to a two-byte string.
+.IP MKS$(X) 12
+Converts a single precision expression to a four-byte string.
+.IP MKD$(X) 12
+Converts a double precision expression to a eight-byte string.
+.IP OCT$(X) 12
+Returns the string which represents the octal value of the decimal
+argument. X is rounded to an integer using CINT before OCTS is evaluated.
+.IP PEEK(I) 12
+Returns the byte read from the indicated memory. (Of limited use
+in the context of ACK)
+.IP POS(I) 12
+Returns the current cursor position. To be implemented.
+.IP RIGHT$(X$,I)
+Returns the right most I characters of string X$.
+If I=0 then the empty string is returned.
+.IP RND(X) 12
+Returns a random number between 0 and 1. X is a dummy argument.
+.IP SGN(X) 12
+If X>0 , SGN(X) returns 1.
+.br
+if X=0, SGN(X) returns 0.
+.br
+if X<0, SGN(X) returns -1.
+.IP SIN(X) 12
+Returns the sine of X in radians.
+.IP SPACE$(X) 12
+Returns  a string of spaces length X. The expression
+X is rounded to an integer using CINT.
+.IP STR$(X)
+Returns the string representation value of X.
+.IP STRING$(I,J) 12
+Returns thes string of length Iwhose characters all
+have ASCII code J. (or first character when J is a string)
+.IP TAB(I) 12
+Spaces to position I on the terminal. If the current
+print position is already beyond space I,TAB
+goes to that position on the next line.
+Space 1 is leftmost position, and the rightmost position
+is width minus 1. To be used within PRINT statements only.
+.IP TAN(X) 12
+Returns the tangent of X in radians. If TAN overflows
+the "Overflow" message is displayed.
+.IP VAL(X$) 12
+Returns the numerical value of string X$.
+The VAL function strips leading blanks and tabs from the
+argument string.
+.SH
+APPENDIX A DIFFERENCES WITH MICROSOFT BASIC
+.LP
+The following list of Microsoft commands and statements are
+not recognized by the compiler.
+.DS
+SPC
+USR
+VARPTR
+AUTO
+CHAIN
+CLEAR	
+CLOAD
+COMMON
+CONT
+CSAVE
+DELETE
+EDIT
+ERASE
+FRE
+KILL
+LIST
+LLIST
+LOAD
+LPRINT
+MERGE
+NAME
+NEW
+NULL
+RENUM
+RESUME
+RUN
+SAVE
+WAIT
+WIDTH LPRINT
+.DE
+Some statements are in the current implementation not available,
+but will be soon. These include:
+.DS
+CALL
+DEFUSR
+FIELD
+GET
+INKEY
+INPUT$
+INSTR$
+LEFT$
+LSET
+RSET
+PUT
+.DE

doc/cg.doc

@@ -1,3 +1,4 @@
+.\" $Header$
 .RP
 .TL
 The table driven code generator from 
@@ -1039,6 +1040,17 @@ Argument to be formatted will be 'full'.
 .IP off_fmt
 Format to be used for integer part of label+constant,
 argument will be 'full'.
+.IP fmt_ilb(ip,il,s)
+Must use the numbers 
+.I ip
+and 
+.I il
+which are a procedure number
+and a label number respectively and copy a string to
+.I s
+that must be unique for that combination.
+This procedure is optional, if it is not given ilb_fmt
+must be defined as below.
 .IP ilb_fmt
 Format to be used for creation of unique instruction labels.
 Arguments will be a unique procedure number (int) and the label
@@ -1069,6 +1081,14 @@ into the datastream.
 .IP con_dlb(s)
 Must generate output that will put the address of the data label
 into the datastream.
+.IP fmt_id(sf,st)
+Must take the string in
+.I sf
+which is a nonnumeric global label, and transform it into a copy made to
+.I st
+which will not collide with reserved assembler words and system labels.
+This procedure is optional, if it is not given the id_first macro is used
+as defined below.
 .IP id_first
 Must be a character.
 This is prepended to all nonnumeric global labels if their length

doc/cref.doc

@@ -1,3 +1,4 @@
+.\" $Header$
 .ll 72
 .nr ID 4
 .de hd
@@ -132,6 +133,8 @@ properties of the Ack-C frontend.
 .IT "2.2 Identifiers"
 External identifiers are unique up to 7 characters and allow
 both upper and lower case.
+.IT "2.3 Keywords"
+The word \fBvoid\fP is also reserved as a keyword.
 .IT "2.4.3 Character constants"
 The ASCII-mapping is used when a character is converted to an
 integer.
@@ -139,11 +142,12 @@ integer.
 To prevent loss of precision the compiler does not perform
 floating point constant folding.
 .IT "2.6 Hardware characteristics"
-The size of objects of the several arithmetic types and the two
-pointer types depend on the EM-implementation used.
+The size of objects of the several arithmetic types and 
+pointers depend on the EM-implementation used.
 The ranges of the arithmetic types depend on the size used,
 the C-frontend assumes two's complement representation for the
-integral types. All sizes are multiples of bytes.
+integral types.
+All sizes are multiples of bytes.
 The calling program \fIack\fP[4] passes information about the
 size of the types to the compiler proper.
 .br
@@ -151,32 +155,27 @@ However, a few general remarks must be made:
 .sp 1
 .IS
 .PT (a)
-Two different pointer types exist: pointers to data and
-pointers to functions.
-The latter type is twice as large as the former.
-Pointers to functions use the same format as Pascal procedure
-parameters, thereby allowing C to use Pascal procedure
-parameters and vice-versa.
-The extra information passed indicates the scope level of the
-procedure.
-.PT (b)
-The size of pointers to data is a multiple of
+The size of pointers is a multiple of
 (or equal to) the size of an \fIint\fP.
-.PT (c)
+.PT (b)
 The following relations exist for the sizes of the types
 mentioned:
 .br
 .ti +5
 \fIchar<=short<=int<=long\fP
-.PT (d)
+.PT (c)
 Objects of type \fIchar\fP use one 8-bit byte of storage,
 although several bytes are allocated sometimes.
-.PT (e)
+.PT (d)
 All sizes are in multiples of bytes.
-.PT (f)
+.PT (e)
 Most EM implementations use 4 bytes for floats and 8 bytes
 for doubles, but exceptions to this rule occur.
 .IE
+.IT "4 What's in a name"
+The type \fIvoid\fP is added.
+Objects of type void do not exist.
+Functions declared as returning void, do not return a value at all.
 .IT "6.1 Characters and integers"
 Objects of type \fIchar\fP are unsigned and do not cause
 sign-extension when converted to \fIint\fP.
@@ -186,8 +185,16 @@ Floating point numbers are truncated towards zero when
 converted to the integral types.
 .IT "6.4 Pointers and integers"
 When a \fIlong\fP is added to or subtracted from a pointer and
-longs are larger then data pointers the \fIlong\fP is converted to an
+longs are larger then pointers the \fIlong\fP is converted to an
 \fIint\fP before the operation is performed.
+.IT "7.2 Unary operators"
+It is allowed to cast any expression to the type \fIvoid\fP.
+.IT "8.2 Type specifiers"
+One type is added to the type-specifiers:
+.br
+.IS
+void
+.IE
 .IT "8.5 Structure and union declarations"
 The only type allowed for fields is \fIint\fP.
 Fields with exactly the size of \fIint\fP are signed,
@@ -199,8 +206,15 @@ Initialization of structures containing bit fields is not
 allowed.
 There is one restriction when using an 'address expression' to initialize
 an integral variable.
-The integral variable must have the size of a data pointer.
+The integral variable must have the same size as a pointer.
 Conversions altering the size of the address expression are not allowed.
+.IT "9.10 Return statement"
+Return statements of the form:
+.IS
+	return ;
+.IE
+are the only form of return statement allowed in a function of type
+function returning void.
 .IT "10.1 External function definitions"
 The total amount for storage used for parameters
 in any function must be less then 4096 bytes.
@@ -226,15 +240,8 @@ int and back will not always result in the same pointer.
 The process mentioned above works with integrals
 of the same size or larger as pointers in all EM implementations
 having such integrals.
-Note that pointers to functions have
-twice the size of pointers to data.
-When converting data pointers to an integral type or vice-versa,
-the pointers is seen as an unsigned with the same size a data-pointer.
-When converting function pointers to anything else the static link part
-of the pointer is discarded,
-the resulting value is treated as if it were a data pointer.
-When converting a data pointer or object of integral type to a function pointer
-a static link with the value 0 is added to complete the function pointer.
+When converting pointers to an integral type or vice-versa,
+the pointers is seen as an unsigned int.
 .br
 EM guarantees that any object can be placed at a word boundary,
 this allows the C-programs to use \fIint\fP pointers

doc/em/Makefile

@@ -7,6 +7,9 @@ IOP=../../util/ass/ip_spec.t
 doc.pr: $(FILES) itables em.i
 	tbl $(FILES) | $(NROFF) >doc.pr
 
+distr:	$(FILES) itables em.i
+	tbl $(FILES) | nroff -Tlp >doc.pr
+
 opr:	doc.pr
 	make pr | opr
 

doc/em/assem.nr

@@ -133,9 +133,9 @@ can be followed by a letter I, U or F.
 This indicator
 specifies the type of the initializer: Integer, Unsigned or Float.
 If no indicator is present I is assumed.
-The size of the object is the wordsize unless
+The size of the initializer is the wordsize unless
 the indicator is followed by an integer specifying the
-object's size.
+initializer's size.
 This integer is governed by the same restrictions as for
 transfer of objects to/from memory.
 As in instruction arguments, initializers include expressions of the form:
@@ -145,8 +145,9 @@ The 'IUF' indicators cannot be used in the offsets.
 .P
 Data labels are referred to by their name.
 .P
+
 Strings are surrounded by double quotes (").
-Semecolon's in string do not indicate the start of comment.
+Semicolon's in string do not indicate the start of comment.
 In the ASCII representation the escape character \e (backslash)
 alters the meaning of subsequent character(s).
 This feature allows inclusion of zeroes, graphic characters and
@@ -175,7 +176,6 @@ the backslash is ignored.
 Example: CON "hello\e012\e0".
 Each string element initializes a single byte.
 The ASCII character set is used to map characters onto values.
-Strings are padded with zeroes up to a multiple of the wordsize.
 .P
 Instruction labels are referred to as *1, *2, etc.  in both branch
 instructions and as initializers.
@@ -209,6 +209,10 @@ l l l.
 .S4 Storage declaration
 Initialized global data is allocated by the pseudoinstruction CON,
 which needs at least one argument.
+Each argument is used to allocate and initialize a number of
+consequtive bytes in data memory.
+The number of bytes to be allocated and the alignment depend on the type
+of the argument.
 For each argument, an integral number of words,
 determined by the argument type, is allocated and initialized.
 .P
@@ -245,8 +249,10 @@ It is not allowed to have more than one HOL block per procedure.
 .P
 The alignment restrictions are enforced by the
 pseudoinstructions.
-All objects are aligned on a multiple of their size or the wordsize
+All initializers are aligned on a multiple of their size or the wordsize
 whichever is smaller.
+Strings form an exception, they are to be seen as a sequence of initializers
+each for one byte, i.e. strings are not padded with zero bytes.
 Switching to another type of fragment or placing a label forces
 word-alignment.
 There are three types of fragments in global data space: CON, ROM and
@@ -382,6 +388,17 @@ May not be preceded by any other pseudo, except MES's.
 .PT "MES 9,<cst>"
 Guarantees that no more than <cst> bytes of parameters are
 accessed, either directly or indirectly.
+.PT "MES 10,<cst>[,<par>]*
+This message number is reserved for the global optimizer.
+It inserts these messages in its output as hints to backends.
+<cst> indicates the type of hint.
+.PT "MES 11"
+Procedures containing this message are possible destinations of
+non-local goto's with the GTO instruction.
+Some backends keep locals in registers,
+the locals in this procedure should not be kept in registers and
+all registers containing locals of other procedures should be
+saved upon entry to this procedure.
 .PE 1
 .VS 1 1
 Each backend is free to skip irrelevant MES pseudos.
@@ -555,7 +572,7 @@ l l 15 l l.
 \&\*n:cst:>= 0:counter
 \&\*s:cst:>0 , word multiple:object size
 \&\*z:cst:>= 0 , zero or word multiple:object size
-\&\*o:cst:>= 0 , word multiple or fraction:object size
+\&\*o:cst:> 0 , word multiple or fraction:object size
 \&\*w:cst:> 0 , word multiple:object size *
 \&\*p:pro::pro identifier
 \&\*b:ilb:>= 0:label number

doc/em/descr.nr

@@ -114,8 +114,7 @@ then fetch the new PC from the list of instruction pointers by indexing with
 index-lower.
 The table does not contain the value of the upper bound,
 but the value of upper-lower as an unsigned integer.
-If the index is out of bounds or if the fetched pointer is 0,
-then fetch the default instruction pointer.
+The default instruction pointer is used when the index is out of bounds.
 If the resulting PC is 0, then trap.
 .P
 CSB selects the new PC by searching.

doc/em/em.i

@@ -240,7 +240,7 @@ begin if (a<0) or (a>maxoffs)
 end;
 
 function argo(a:double):size;
-begin if (a<0) or (a>maxoffs)
+begin if (a<=0) or (a>maxoffs)
 	then trap(EODDZ)
 	else if (a mod wsize<>0) and (wsize mod a<>0) then trap(EODDZ);
       argo:=a ;
@@ -1504,10 +1504,9 @@ begin
 	 end;
     CSA: begin k:=argw(k); if k<>wsize then trap(EILLINS);
 	   a:=popa;
-	   st:= popsw - signwd(memw(a+asize)); b:=0;
+	   st:= popsw - signwd(memw(a+asize));
 	   if (st>=0) and (st<=memw(a+wsize+asize)) then
-	      b:=mema(a+2*wsize+asize+asize*st);
-	   if b=0 then b:=mema(a);
+	      b:=mema(a+2*wsize+asize+asize*st) else b:=mema(a);
 	   if b=0 then trap(ECASE) else newpc(b)
 	 end;
     CSB: begin k:=argw(k); if k<>wsize then trap(EILLINS); a:=popa;

doc/em/int/em.p

@@ -281,7 +281,7 @@ begin if (a<0) or (a>maxoffs)
 end;
 
 function argo(a:double):size;
-begin if (a<0) or (a>maxoffs)
+begin if (a<=0) or (a>maxoffs)
 	then trap(EODDZ)
 	else if (a mod wsize<>0) and (wsize mod a<>0) then trap(EODDZ);
       argo:=a ;
@@ -683,7 +683,7 @@ begin
   a:=argp(uerrorproc);
   uerrorproc:=0;              { reset signal }
   call(a);                    { call the routine }
-  intrap:=false;              { Don't catch recursive traps anymore }
+  intrap:=false;              { Do not catch recursive traps anymore }
   goto 8888;                  { reenter main loop }
 end;
 
@@ -1149,7 +1149,7 @@ end;
 	jmp (r2)               /done
 
   The important thing to notice is where and how the operand fetch occurred:
-       lol2, lol4, and lol6, (the mini's) have implicit operands
+       lol2, lol4, and lol6, (the minis) have implicit operands
        lolb knew it had to fetch one byte, and did so without any table lookup
        lolw knew it had to fetch a word, and did so, high order byte first }
 {
@@ -1604,10 +1604,9 @@ begin
 	 end;
     CSA: begin k:=argw(k); if k<>wsize then trap(EILLINS);
 	   a:=popa;
-	   st:= popsw - signwd(memw(a+asize)); b:=0;
+	   st:= popsw - signwd(memw(a+asize));
 	   if (st>=0) and (st<=memw(a+wsize+asize)) then
-	      b:=mema(a+2*wsize+asize+asize*st);
-	   if b=0 then b:=mema(a);
+	      b:=mema(a+2*wsize+asize+asize*st) else b:=mema(a);
 	   if b=0 then trap(ECASE) else newpc(b)
 	 end;
     CSB: begin k:=argw(k); if k<>wsize then trap(EILLINS); a:=popa;

doc/em/ispace.nr

@@ -45,6 +45,7 @@ the trapping instruction (see next chapter).
 the GTO instruction, which is used for non-local goto's.
 It can remove several frames from the stack and transfer
 control to an active procedure.
+(see also MES~11 in paragraph 11.1.4.4)
 .PE
 .IE
 .P

doc/i80.doc

@@ -0,0 +1,830 @@
+." $Header$
+.RP
+.TL
+Back end table for the Intel 8080 micro-processor
+.AU
+Gerard Buskermolen
+.AB
+A back end is a part of the Amsterdam Compiler Kit (ACK).
+It translates EM, a family of intermediate languages, into the
+assembly language of some target machine, here the Intel 8080 and Intel 8085 microprocessors.
+.AE
+.NH1
+INTRODUCTION
+.PP
+To simplify the task of producing portable (cross) compilers and 
+interpreters, the Vrije Universiteit designed an integrated collection
+of programs, the Amsterdam Compiler Kit (ACK).
+It is based on the old UNCOL-idea ([4]) which attempts to solve the problem
+of making a compiler for each of
+.B N
+languages on
+.B M
+different machines without having to write
+.B N\ *\ M
+programs.
+.sp 1
+The UNCOL approach is to write
+.B N
+"front ends", each of which translates one source language into
+a common intermediate language, UNCOL (UNiversal Computer Oriented
+Language), and
+.B M
+"back ends", each of which translates programs in UNCOL into a
+specific machine language.
+Under these conditions, only
+.B N\ +\ M
+programs should be written to provide all
+.B N
+languages on all
+.B M
+machines, instead of
+.B N\ *\ M
+programs.
+.sp 1
+The intermediate language for the Amsterdam Compiler Kit is the machine
+language for a simple stack machine called EM (Encoding Machine).
+So a back end for the Intel 8080 micro translates EM code into
+8080 assembly language.
+.sp 1
+The back end is a single program that is driven by a machine dependent
+driving table.
+This driving table, or back end table, 
+defines the mapping from EM code to the machine's assembly language.
+.NH 1
+THE 8080 MICRO PROCESSOR
+.PP
+This back end table can be used without modification for the Intel 8085
+processor.
+Except for two additional instructions, the 8085 instruction set
+is identical and fully compatible with the 8080 instruction set.
+So everywhere in this document '8080' can be read as '8080 and 8085'.
+.NH 2
+Registers
+.PP
+The 8080 processor has an 8 bit accumulator,
+six general purpose 8-bit registers,
+a 16 bit programcounter and a 16 bit stackpointer.
+Assembler programs can refer the accumulator by A and 
+the general purpose registers by B, C, D, E, H and L. (*)
+.FS
+* In this document 8080 registers and mnemonics are referenced by capitals, for the sake of clarity.
+Nevertheless the assembler expects small letters.
+.FE
+Several instructions address registers in groups of two, thus creating
+16 bit registers:
+.DS
+Registers referenced:   Symbolic reference:
+      B and C                   B
+      D and E                   D
+      H and L                   H
+.DE
+The first named register, contains the high order byte
+(H and L stand for High and Low).
+.br
+The instruction determines how the processor interprets the reference.
+For example, ADD B is an 8 bit operation, adding the contents of 
+register B to accumulator A. By contrast PUSH B is a 16 bit operation
+pushing B and C onto the stack.
+.sp 1
+There are no index registers.
+.sp 1
+.NH 2
+Flip-flops
+.PP
+The 8080 microprocessor provides five flip-flops used as condition flags
+(S, Z, P, C, AC) and one interrupt enable flip-flop IE.
+.br
+The sign bit S is set (cleared) by certain instructions when the most significant
+bit of the result of an operation equals one (zero).
+.br
+The zero bit Z is set (cleared) by certain operations when the
+8-bit result of an operation equals (does not equal) zero.
+.br
+The parity bit P is set (cleared) if the 8-bit result of an
+operation includes an even (odd) number of ones.
+.br
+C is the normal carry bit.
+.br
+AC is an auxiliary carry that indicates whether there has been a carry
+out of bit 3 of the accumulator.
+This auxiliary carry is used only by the DAA instruction, which
+adjusts the 8-bit value in the accumulator to form two 4-bit
+binary coded decimal digits.
+Needless to say this instruction is not used in the back-end.
+.sp 1
+The interrupt enable flip-flop IE is set and cleared under
+program control using the instructions EI (Enable Interrupt) and
+DI (Disable Interrupt).
+It is automatically cleared when the CPU is reset and when
+an interrupt occurs, disabling further interrupts until IE = 1 again.
+.NH 2
+Addressing modes
+.NH 3
+Implied addressing
+.PP
+The addressing mode of some instructions is implied by the instruction itself.
+For example, the RAL (rotate accumulator left) instruction deals only with
+the accumulator, and PCHL loads the programcounter with the contents
+of register-pair HL.
+.NH 3
+Register addressing
+.PP
+
+With each intruction using register addressing,
+only one register is specified (except for the MOV instruction),
+although in many of them the accumulator is implied as
+second operand.
+Examples are CMP E, which compares register E with the accumulator,
+and DCR B, which decrements register B.
+.br
+A few instructions deal with 16 bit register-pairs:
+examples are DCX B, which decrements register-pair BC and the 
+PUSH and POP instructions.
+.NH 3
+Register indirect addressing
+.PP
+Each instruction that may refer to an 8 bit register, may
+refer also to a memory location. In this case the letter M
+(for Memory) has to be used instead of a register.
+It indicates the memory location pointed to by H and L,
+so ADD M adds the contents of the memory location specified
+by H and L to the contents of the accumulator.
+.br
+The register-pairs BC and DE can also be used for indirect addressing,
+but only to load or store the accumulator.
+For example, STAX B stores the contents of the accumulator
+into the memory location addressed by register-pair BC.
+.NH 3
+Immediate addressing
+.PP
+The immediate value can be an 8 bit value, as in ADI 10 which
+adds 10 to the accumulator, or a 16 bit value, as in 
+LXI H,1000, which loads 1000 in the register-pair HL.
+.NH 3
+Direct addressing
+.PP
+Jump instructions include a 16 bit address as part of the instruction.
+.br
+The instruction SHLD 1234 stores the contents of register
+pair HL on memory locations 1234 and 1235.
+The high order byte is stored at the highest address.
+.NH 1
+THE 8080 BACK END TABLE
+.PP
+The back end table is designed as described in [5].
+So for an overall design of a back end table I refer to this document.
+.br
+This section deals with problems encountered in writing the
+8080 back-end table.
+Some remarks are made about particular parts
+of the table that might not seem clear at first sight.
+.NH 2
+Constant definitions
+.PP
+Word size (EM_WSIZE) and pointer size (EM_PSIZE) are both 
+defined as two bytes.
+The hole between AB and LB (EM_BSIZE) is four bytes: only the
+return address and the localbase are saved.
+.NH 2
+Registers and their properties
+.PP
+All properties have the default size of two bytes, because one-byte
+registers also cover two bytes when put on the real stack.
+.sp 1
+The next considerations led to the choise of register-pair BC 
+as localbase.
+Though saving the localbase in memory would leave one more register-pair
+available as scratch register, it would slow down instructions
+as 'lol' and 'stl' too much.
+So a register-pair should be sacrificed as localbase.
+Because a back-end without a free register-pair HL is completely
+broken-winged, the only reasonable choises are BC and DE.
+Though the choise between them might seem arbitrary at first sight,
+there is a difference between register-pairs BC and DE:
+the instruction XCHG exchanges the contents of register-pairs DE and
+HL.
+When DE and HL are both heavily used on the fake-stack, this instruction
+is very usefull.
+Since it won't be usefull too often to exchange HL with the localbase
+and since an instruction exchanging BC and HL does not exist, BC is
+chosen as localbase.
+.sp 1
+Many of the register properties are never mentioned in the
+PATTERNS part of the table.
+They are only needed to define the INSTRUCTIONS correctly.
+.sp 1
+The properties really used in the PATTERNS part are:
+.IP areg: 24
+the accumulator only
+.IP reg:
+any of the registers A, D, E, H or L. Of course the registers B and C which are
+used as localbase don't possess this property.
+When there is a single register on the fake-stack, its value
+is always considered non-negative.
+.IP dereg:
+register-pair DE only
+.IP hlreg:
+register-pair HL only
+.IP hl_or_de:
+register-pairs HL and DE both have this property
+.IP localbase:
+used only once (i.e. in the EM-instruction 'str 0')
+.PP
+.sp 1
+The stackpointer SP and the processor status word PSW have to be
+defined explicitely because they are needed in some instructions
+(i.e. SP in LXI, DCX and INX and PSW in PUSH and POP).
+.br
+It doesn't matter that the processor status word is not just register A
+but includes the condition flags.
+.NH 2
+Tokens
+.PP
+The tokens 'm' and 'const1' are used in the INSTRUCTIONS- and MOVES parts only.
+They will never be on the fake-stack.
+.sp 1
+The token 'label' reflects addresses known at assembly time.
+It is used to take full profit of the instructions LHLD
+(Load HL Direct) and SHLD (Store HL Direct).
+.sp 1
+Compared with many other back-end tables, there are only a small number of
+different tokens (four).
+Reasons are the limited addressing modes of the 8080 microprocessor,
+no index registers etc.
+.br
+For example to translate the EM-instruction
+.DS
+lol 10
+.DE
+the next 8080 instructions are generated:
+.DS L
+LXI H,10        /* load registers pair HL with value 10 */
+DAD B           /* add localbase (BC) to HL             */
+MOV E,M         /* load E with byte pointed to by HL    */
+INX H           /* increment HL                         */
+MOV D,M         /* load D with next byte                */
+.DE
+Of course, instead of emitting code immmediately, it could be postponed
+by placing something like a {LOCAL,10} on the fake-stack, but some day the above
+mentioned code will have to be generated, so a LOCAL-token is
+hardly usefull.
+.br
+See also the comment on the load instructions.
+.NH 2
+Sets
+.PP
+Only 'src1or2' is used in the PATTERNS.
+.NH 2
+Instructions
+.PP
+Each instruction indicates whether or not the condition flags
+are affected, but this information will never have any influence
+because there are no tests in the PATTERNS part of the table.
+.sp 1
+For each instruction a cost vector indicates the number of bytes
+the instruction occupies and the number of time periods it takes
+to execute the instruction.
+The length of a time period depends on the clock frequency
+and may range from 480 nanoseconds to 2 microseconds on a 
+8080 system and from 320 nanoseconds to 2 microseconds
+on a 8085 system.
+.sp 1
+In the TOKENS-part the cost of token 'm' is defined as (0,3).
+In fact it usually takes 3 extra time periods when this register indirect mode
+is used instead of register mode, but since the costs are not completely
+orthogonal this results in small deficiencies for the DCR, INR and MOV
+instructions.
+Although it is not particularly usefull these deficiencies are
+corrected in the INSTRUCTIONS part, by treating the register indirect
+mode seperately.
+.sp 1
+The costs of the conditional call and return instructions really
+depend on whether or not the call resp. return is actually made.
+Unimportant.
+.sp 1
+Instructions not used in this table have been commented out.
+Of course many of them are used in the library routines.
+.NH 2
+Moves
+.PP
+This section is supposed to be straight-forward.
+.NH 2
+Tests
+.PP
+The TESTS section is only included to refrain
+.B cgg
+from complaining.
+.NH 2
+Stackingrules
+.PP
+When, for example, the token {const2,10} has to be stacked while
+no free register-pair is available, the next code is generated:
+.DS
+PUSH H
+LXI H,10
+XTHL
+.DE
+The last instruction exchanges the contents of HL with the value
+on top of the stack, giving HL its original value again.
+.NH 2
+Coercions
+.PP
+The coercion to unstack register A, is somewhat tricky,
+but unfortunately just popping PSW leaves the high-order byte in
+the accumulator.
+.sp 1
+The cheapest way to coerce HL to DE (or DE to HL) is by using
+the XCHG instruction, but it is not possible to explain
+.B cgg
+this instruction in fact exchanges the contents of these
+register-pairs.
+Before the coercion is carried out other appearances of DE and HL
+on the fake-stack will be moved to the real stack, because in
+the INSTRUCTION-part is told that XCHG destroyes the contents
+of both DE and HL.
+.br
+The coercion transposing one register-pair to another one by
+emitting two MOV-instructions, will be used only if
+one of the register-pairs is the localbase.
+.NH 2
+Patterns
+.PP
+As a general habit I have allocated (uses ...) all registers
+that should be free to generate the code, although it is not
+always necessary.
+For example in the code rule
+.DS
+pat loe
+uses hlreg
+gen lhld {label,$1}                   yields hl
+.DE
+the 'uses'-clause could have been omitted because 
+.B cgg
+knows that LHLD destroyes register-pair HL.
+.sp 1
+Since there is only one register with property 'hlreg',
+there is no difference between 'uses hlreg' (allocate a
+register with property 'hlreg') and 'kills hlreg' (remove
+all registers with property 'hlreg' from the fake-stack).
+The same applies for the property 'dereg'.
+.br
+As a consequence 'kills' is rarely used in this back-end table.
+.NH 3
+Group 1: Load instructions
+.PP
+When a local variable must be squared, there will probably be EM-code like:
+.DS
+lol 10
+lol 10
+mli 2
+.DE
+When the code for the first 'lol 10' has been executed, DE contains the
+wanted value.
+To refrain 
+.B cgg
+from emitting the code for 'lol 10' again, an extra
+pattern is included in the table for cases like this.
+.br
+The same applies for two consecutive 'loe'-s or 'lil'-s.
+.sp 1
+A bit tricky is 'lof'.
+It expects either DE or HL on the fake-stack, moves {const2,$1}
+into the other one, and eventually adds them.
+The 'kills' part is necessary here because if DE was on the fake-stack,
+.B cgg
+doesn't see that the contents of DE is destroyed by the code
+(in fact 'kills dereg' would have been sufficient: because of the
+DAD instruction 
+.B cgg
+knows that HL is destroyed).
+.sp 1
+By lookahead,
+.B cgg
+can make a clever choise between the first and
+second code rule of 'loi 4'.
+The same applies for several other instructions.
+.NH 3
+Group 2: Store instructions
+.PP
+A similar idea as with the two consecutive identical load instructions
+in Group 1, applies for a store instruction followed by a corresponding load instruction.
+.NH 3
+Groups 3 and 4: Signed and unsigned integer arithmetic
+.PP
+Since the 8080 instruction set doesn't provide multiply and
+divide instructions, special routines are made to accomplish these tasks.
+.sp 1
+Instead of providing four slighty differing routines for 16 bit signed or
+unsigned division, yielding the quotient or the remainder,
+the routines are merged.
+This saves space and assembly time
+when several variants are used in a particular program,
+at the cost of a little speed.
+.br
+When the routine is called, bit 7 of register A indicates whether
+the operands should be considered as signed or as unsigned integers,
+and bit 0 of register A indicates whether the quotient or the
+remainder has to be delivered.
+.br
+The same applies for 32 bit division.
+.sp 1
+The routine doing the 16 bit unsigned multiplication could
+have been used for 16 bit signed multiplication too.
+Nevertheless a special 16 bit signed multiplication routine is
+provided, because this one will usually be much faster.
+.NH 3
+Group 5: Floating point arithmetic
+.PP
+Floating points are not implemented.
+.br
+Whenever an EM-instruction involving floating points is offered
+to the code-generator, it generates the code 'call eunimpl',
+which traps with trap number 63.
+Some of the Pascal and C library routines output floating point
+EM-instructions, so code has to be generated for them.
+Of course this doesn't imply the code will ever be executed.
+.NH 3
+Group 12: Compare instructions
+.PP
+The code for 'cmu 2', with its 4 labels, is terrible.
+But it is the best I could find.
+.NH 3
+Group 9: Logical instructions
+.PP
+I have tried to merge both variants of the instructions 'and 2', 'ior 2' and 'xor 2',
+as in
+.DS
+pat and $1==2
+with hl_or_de hl_or_de
+uses reusing %1, reusing %2, hl_or_de, areg
+gen mov a,%1.2
+    ana %2.2
+    mov %a.2,a
+    mov a,%1.1
+    ana %2.1
+    mov %a.1,a                     yields %a
+.DE
+but the current version of
+.B cgg
+doesn't approve this.
+.br
+In any case
+.B cgg
+chooses either DE or HL to store the result, using lookahead.
+.NH 3
+Group 14: Procedure call instructions
+.PP
+There is an 8 bytes function return area, called '.fra'.
+If only 2 bytes have to be returned, register-pair DE is used.
+.NH 1
+LIBRARY ROUTINES
+.PP
+Most of the library routines start with saving the return address
+and the localbase, so that the parameters are on the top of the stack
+and the registers B and C are available as scratch registers.
+Since register-pair HL is needed to accomplish these tasks,
+and also to restore everything just before the routine returns,
+it is not possible to transfer data between the routines and the
+surrounding world through register H or L. 
+Only registers A, D and E can be used for this.
+.sp
+When a routine returns 2 bytes, they are usually returned in 
+registers-pair DE.
+When it returns more than 2 bytes they are pushed onto the stack.
+.br
+
+It would have been possible to let the 32 bit arithmetic routines
+return 2 bytes in DE and the remaining 2 bytes on the stack
+(this often would have saved some space and execution time),
+but I don't consider that as well-structured programming.
+.NH 1
+TRAPS
+.PP
+Whenever a trap, for example trying to divide by zero,
+occurs in a program that originally was written in C or Pascal,
+a special trap handler is called.
+.br
+This trap handler wants to write an appropriate error message on the
+monitor.
+It tries to read the message from a file (e.g. etc/pc_rt_errors in the
+EM home directory for Pascal programs), but since the 8080 back-end
+doesn't know about files, we are in trouble.
+This problem is solved, as far as possible, by including the 'open'-monitor call in the mon-routine.
+It returns with file descriptor -1.
+The trap handler reacts by generating another trap, with the original
+trap number.
+But this time, instead of calling the C- or Pascal trap handler again,
+the next message is printed on the monitor:
+.DS L
+        trap number <TN>
+        line <LN> of file <FN>
+
+where   <TN> is the trap number (decimal)
+        <LN> is the line number (decimal)
+        <FN> is the filename of the original program
+.DE
+.sp 1
+Trap numbers are subdivided as follows:
+.IP 1-27: 20
+EM-machine error, as described in [3]
+.IP 63:
+an unimplemented EM-instruction is used
+.IP 64-127:
+generated by compilers, runtime systems, etc.
+.IP 128-252:
+generated by user programs
+.NH 1
+IMPLEMENTATION
+.PP
+It will not be possible to run the entire Amsterdam Compiler Kit on a
+8080-based computer system.
+One has to write a program on another 
+system, a system where the compiler kit runs on.
+This program may be a mixture of high-level languages, such as 
+C or Pascal, EM and 8080 assembly code.
+The program should be compiled using the compiler kit, producing 8080 machine code.
+This code should come available to the 8080 machine
+for example by downloading or
+by storing it in ROM (Read Only Memory).
+.sp 1
+Depending on the characteristics of the particular 8080 based system, some
+adaptions have to be made:
+.IP 1) 10 
+In 'head_em': the base address, which is the address where the first
+8080 instruction will be stored, and the initial value of the
+stackpointer are set to 0x1000 and 0x8000 respectivally.
+.br
+Other systems require other values.
+.IP 2)
+In 'head_em': before calling "_m_a_i_n", the environment
+pointer, argument vector and argument count will have to be pushed
+onto the stack.
+Since this back-end is tested on a system without any knowledge
+of these things, dummies are pushed now.
+.IP 3)
+In 'tail_em': proper routines "putchar" and "getchar" should
+be provided.
+They should write resp. read a character on/from the monitor.
+Maybe some conversions will have to be made.
+.IP 4)
+In 'head_em': an application program returns control to the monitor by 
+jumping to address 0xFB52.
+If this is not the right way on your system, change it.
+.IP 5)
+In 'tail_em': the current version of the 8080 back-end has very limited I/O
+capabilities, because it was tested on a system that
+had no knowlegde of files.
+So the implementation of the EM-instruction 'mon' is very simple;
+it can only do the following things:
+.RS
+.IP Monitor\ call\ 1: 40
+Exit
+.IP Monitor\ call\ 3:
+read, always reads from the monitor.
+.br
+echos the read character.
+.br
+ignores file descriptor.
+.IP Monitor\ call\ 4:
+write, always writes on the monitor.
+.br
+ignores file descriptor.
+.IP Monitor\ call\ 5:
+open file, returns file descriptor -1.
+.br
+(compare chapter about TRAPS)
+.IP Monitor\ call\ 6:
+close file, returns error code = 0.
+.IP Monitor\ call\ 54:
+io-control, returns error code = 0.
+.RE
+.sp
+If the system should do file-handling the routine ".mon"
+should be extended thoroughly.
+.NH 1
+INTEL 8080 VERSUS ZILOG Z80 AND INTEL 8086
+.NH 2
+Introduction
+.PP
+At about the same time I develloped the back end
+for the Intel 8080 and Intel 8085,
+Frans van Haarlem did the same job for the Zilog z80 microprocessor.
+Since the z80 processor is an extension of the 8080,
+any machine code offered to a 8080 processor can be offered
+to a z80 too.
+The assembly languages are quite different however.
+.br
+During the devellopments of the back ends we have used
+two micro-computers, both equiped with a z80 microprocessor.
+Of course the output of the 8080 back end is assembled by an
+8080 assembler. This should assure I have never used any of
+the features that are potentially available in the z80 processor,
+but are not part of a true 8080 processor.
+.sp 1
+As a final job, I have
+investigated the differences between the 8080 and z80 processors
+and their influence on the back ends.
+I have tried to measure this influence by examining the length of
+the generated code.
+I have also involved the 8086 micro-processor in this measurements.
+.NH 2
+Differences between the 8080 and z80 processors
+.PP
+Except for some features that are less important concerning back ends,
+there are two points where the z80 improves the 8080:
+.IP First, 18
+the z80 has two additional index registers, IX and IY.
+They are used as in
+.DS
+         LD B,(IX+10)
+.DE
+The offset, here 10, should fit in one byte.
+.IP Second,
+the z80 has several additional instructions.
+The most important ones are:
+.RS
+.IP 1) 8
+The 8080 can only load or store register-pair HL direct
+(using LHLD or SHLD).
+The z80 can handle BC, DE and SP too.
+.IP 2)
+Instructions are included to ease block movements.
+.IP 3)
+There is a 16 bit subtract instruction.
+.IP 4)
+While the 8080 can only rotate the accumulator, the z80
+can rotate and shift each 8 bit register.
+.IP 5)
+Special routines are included to jump to near locations, saving 1 byte.
+.RE
+.NH 2
+Consequences for the 8080 and z80 back end
+.PP
+The most striking difference between the 8080 and z80 back ends
+is the choise of the localbase.
+The writer of the z80 back end chose index register IY as localbase,
+because this results in the cheapest coding of EM-instructions
+like 'lol' and 'stl'.
+.br
+The z80 instructions that load local 10, for example
+.DS
+LD E,(IY+10)
+LD D,(IY+11)
+.DE
+occupy 6 bytes and take 38 time periods to execute.
+The five corresponding 8080 instructions loading a local
+occupy 7 bytes and take 41 time periods.
+Although the profit of the z80 might be not world-shocking,
+it should be noted that as a side effect it may save some
+pushing and popping since register pair HL is not used.
+.sp 1
+The choise of IY as localbase has its drawbacks too.
+The root of the problem is that it is not possible to add
+IY to HL.
+For the EM-instruction
+.DS
+lal 20
+.DE
+the z80 back end generates code like
+.DS
+LD BC,20
+PUSH IY
+POP HL
+ADD HL,BC
+.DE
+leaving the wanted address in HL.
+.br
+This annoying push and pop instructions are also needed in some
+other instructions, for instance in 'lol' when the offset
+doesn't fit in one byte.
+.sp 1
+Beside the choise of the localbase, I think there is no
+fundamental difference between the 8080 and z80 back ends,
+except of course that the z80 back end has register pair BC
+and, less important, index register IX available as scratch registers.
+.sp 1
+Most of the PATTERNS in the 8080 and z80 tables are more or less
+a direct translation of each other.
+.NH 2
+What did I do?
+.PP
+To get an idea of the quality of the code generated by
+the 8080, z80 and 8086 back ends I have gathered
+some C programs and some Pascal programs.
+Then I produced 8080, z80 and 8086 code for them.
+Investigating the assembler listing I found the
+lengths of the different parts of the generated code.
+.br
+I have checked two areas:
+.IP 1) 8
+the entire text part
+.IP 2)
+the text part without any library routine, so only the plain user program
+.LP
+I have to admit that neither one of them is really honest.
+When the entire text part is checked, the result is disturbed
+because not always the same library routines are loaded.
+And when only the user program itself is considered, the result is
+disturbed too.
+For example the 8086 has a multiply instruction,
+so the EM-instruction 'mli 2' is translated in the main program,
+but the 8080 and z80 call a library routine that is not counted.
+Also the 8080 uses library routines at some places where the
+z80 does not.
+.sp 1
+But nevertheless I think the measurements will give an idea
+about the code produced by the three back ends.
+.NH 2
+The results
+.PP
+The table below should be read as follows.
+For all programs I have computed the ratio of the code-lengths
+of the 8080, z80 and 8086.
+The averages of all Pascal/C programs are listed in the table,
+standarized to '100' for the 8080.
+So the listed '107' indicates that the lengths
+of the text parts of the z80 programs that originally were Pascal programs,
+averaged 7 percent larger than in the corresponding 8080 programs.
+.DS C
+ --------------------------------------------------
+|                       |  8080  |   z80  |  8086  |
+ --------------------------------------------------
+| C, text part          |   100  |   103  |    65  |
+| Pascal, text part     |   100  |   107  |    55  |
+| C, user program       |   100  |   110  |    71  |
+| Pascal, user program  |   100  |   118  |    67  |
+ --------------------------------------------------
+.DE
+.TE
+The most striking thing in this table is that the z80 back end appears
+to produce larger code than the 8080 back end.
+The reason is that the current z80 back end table is
+not very elaborate yet.
+For instance it doesn't look for any EM-pattern longer than one.
+So the table shows that the preparations in the 8080 back end table
+to produce faster code (like recognizing special EM-patterns
+and permitting one byte registers on the fake-stack)
+was not just for fun, but really improved the generated code
+significantly.
+.sp 1
+The table shows that the 8080 table is relativelly better
+when only the plain user program is considered instead  of the entire text part.
+This is not very surprising since the 8080 back end sometimes
+uses library routines where the z80 and especially the 8086 don't.
+.sp 1
+The difference between the 8080 and z80 on the one hand and the 8086
+on the other is very big.
+But of course it was not equal game:
+the 8086 is a 16 bit processor that is much more advanced than the
+8080 or z80 and the 8086 back end is known to produce
+very good code.
+.bp
+.B REFERENCES
+.sp 2
+.IP [1] 10
+8080/8085 Assembly Language Programming Manual,
+.br
+Intel Corporation (1977,1978)
+.IP [2]
+Andrew S. Tanenbaum, Hans van Staveren, E.G. Keizer and Johan W. Stevenson,
+.br
+A practical tool kit for making portable compilers,
+.br
+Informatica report 74, Vrije Universiteit, Amsterdam, 1983.
+.sp
+An overview on the Amsterdam Compiler Kit.
+.IP [3]
+Tanenbaum, A.S., Stevenson, J.W., Keizer, E.G., and van Staveren, H.
+.br
+Desciption of an experimental machine architecture for use with block
+structured languages,
+.br
+Informatica report 81, Vrije Universiteit, Amsterdam, 1983.
+.sp
+The defining document for EM.
+.IP [4]
+Steel, T.B., Jr.
+.br
+UNCOL: The myth and the Fact. in Ann. Rev. Auto. Prog.
+.br
+Goodman, R. (ed.), vol. 2, (1960), p325-344.
+.sp
+An introduction to the UNCOL idea by its originator.
+.IP [5]
+van Staveren, Hans
+.br
+The table driven code generator from the Amsterdam Compiler Kit
+(Second Revised Edition),
+.br
+Vrije Universiteit, Amsterdam.
+.sp
+The defining document for writing a back end table.
+.IP [6]
+Voors, Jan
+.br
+A back end for the Zilog z8000 micro,
+.br
+Vrije Universiteit, Amsterdam.
+.sp
+A document like this one, but for the z8000.

doc/pcref.doc

@@ -1,3 +1,4 @@
+.\" $Header$
 .ds OF \\fBtest~off:~\\fR
 .ds ON \\fBtest~on:~~\\fR
 .ds AL \\fBtest~all:~\\fR
@@ -412,6 +413,36 @@ for parameters. Some EM implementations check this:
 \*(ONnot checked.
 .I2
 not checked.
+.IE
+.PP
+For those who wish the use the interface between C and Pascal we
+give an incomplete list of corresponding formal parameters in C and Pascal.
+.sp 1
+.ta 8 37
+.nf
+	Pascal	C
+	a:integer	int a
+	a:char	int a
+	a:boolean	int a
+	a:real	double a
+	a:^type	type *a
+	var a:type	type *a
+	procedure a(pars)	struct {
+		     void (*a)() ;
+		     char *static_link ;
+		}
+	function a(pars):type	struct {
+		     type (*a)() ;
+		     char *static_link ;
+		}
+.fi
+The Pascal runtime system uses the following algorithm when calling
+function/procedures passed as parameters.
+.nf
+.ta 8 16
+	if ( static_link ) (*a)(static_link,pars) ;
+	else               (*a)(pars) ;
+.fi
 .IT 6.7.2.1
 The order of evaluation of the operands of a dyadic operator
 shall be implementation-dependent.
@@ -1303,6 +1334,19 @@ Alternate symbol representation.
 .sp
 The comment delimiters '(*' and '*)' are recognized and treated like '{' and '}'.
 The other alternate representations of symbols are not recognized.
+.sp
+.ti -3
+9.~\
+Pre-processing.
+.sp
+If the very first character of a file containing a Pascal
+program is the sharp ('#', ASCII 23(hex)) the file is preprocessed
+in the same way as C programs.
+Lines beginning with a '#' are taken as preprocessor command lines
+and not fed to the Pascal compiler proper.
+C style comments, /*......*/, are removed by the C preprocessor,
+thus C comments inside Pascal programs are also removed when they
+are fed through the preprocessor.
 .CH "Deviations from the standard"
 Ack-Pascal deviates from the (March 1980) standard proposal in the following ways:
 .IS

doc/peep.doc

@@ -1,3 +1,4 @@
+.\" $Header$
 .TL
 Internal documentation on the peephole optimizer
 .br

doc/regadd.doc

@@ -1,3 +1,4 @@
+.\" $Header$
 .TL
 Addition of register variables to an existing table.
 .NH 1

doc/toolkit.doc

@@ -1,3 +1,4 @@
+.\" $Header$
 .RP
 .ND
 .nr LL 78m

doc/v7bugs.doc

@@ -1,3 +1,4 @@
+.\" $Header$
 .wh 0 hd
 .wh 60 fo
 .de hd

doc/val.doc

@@ -1,3 +1,4 @@
+.\" $Header$
 .ll 72
 .wh 0 hd
 .wh 60 fo

doc/z80.doc

@@ -0,0 +1,68 @@
+THE Z80 BACK END TABLE
+
+INTRODUCTION
+
+This table was written to make it run, not to make it clever!
+The effect is, that the table written for the intel 8080, 
+which was made very clever runs faster and requiers less space!!
+So, for anyone to run programs on a z80 machine:
+You could try to make the table as clever as the one for the i80,
+or you could run the i80 table, for that can run on every z80 too.
+
+IMPLEMENTATION
+
+It will not be possible to run the entire Amsterdam Compiler Kit on a
+Z80-based computer system.
+One has to write a program on another 
+system, a system where the compiler kit runs on.
+This program may be a mixture of high-level languages, such as 
+C or Pascal, EM and z80 assembly code.
+The program should be compiled using the compiler kit,
+producing z80 machine code.
+This code should come available to the z80 machine
+for example by downloading or
+by storing it in ROM (Read Only Memory).
+Depending on the characteristics of the particular z80 based system, some
+adaptions have to be made:
+1) In 'head_em': the base address, which is the address where the first
+   z80 instruction will be stored, and the initial value of the
+   stackpointer are set to 0x1000 and 0x7ffe respectivally.
+   The latter because it could run on a 32K machine as well.
+   Other systems require other values.
+2) In 'head_em': before calling "_m_a_i_n", the environment
+   pointer, argument vector and argument count will have to be pushed
+   onto the stack.
+   Since this back-end is tested on a system without any knowledge
+   of these things, dummies are pushed now.
+3) In 'tail_em': proper routines "putchar" and "getchar" should
+   be provided.
+   They should write resp. read a character on/from the monitor.
+   Maybe some conversions will have to be made.
+   The ones for the Nascom and Hermac z80 micro's are to be found
+   in the EM-library.
+4) In 'head_em': an application program returns control to the monitor by 
+   jumping to address 0x20.
+   If this is not the right way on your system, change it.
+   For an CPM-machine for example this should be 0x5, to provide a warm boot.
+5) In 'tail_em': the current version of the z80 back-end has very limited I/O
+   capabilities, because it was tested on a system that
+   had no knowlegde of files.
+   So the implementation of the EM-instruction 'mon' is very simple;
+   it can only do the following things:
+   Monitor call 1:
+		Exit
+   Monitor call 3:
+   		read, always reads from the monitor.
+		echos the read character.
+		ignores file descriptor.
+   Monitor call 4:
+		write, always writes on the monitor.
+		ignores file descriptor.
+   Monitor call 5:
+		open file, returns file descriptor -1.
+   Monitor call 6:
+		close file, returns error code = 0.
+   Monitor call 54:
+		io-control, returns error code = 0.
+If the system should do file-handling the routine ".mon"
+should be extended thoroughly.

emtest/Makefile

@@ -0,0 +1,19 @@
+tested:		last
+	set -x ;\
+		for i in `awk '{for(i=\$$1;i<=127;i++)print i}' last ` ;\
+		do \
+		  echo $$i; \
+		  echo $$i >last; \
+		  select $$i tests > test.e; \
+		  ack test.e; \
+		  a.out \
+		  : ok; \
+		done
+		rm -f test.e a.out
+		>tested
+
+last:		tests test.h select
+		echo 0 >last
+
+select:		select.c
+		cc -O -n -o select select.c

emtest/READ_ME

@@ -0,0 +1,136 @@
+This directory contains test programs for EM implementations.
+The test programs are all part of the file "tests".
+Each individual test program looks like:
+
+	TEST 004: test ...
+	 ...		; data declarations etc.
+	MAIN nlocal
+	 ...		; part of the body of MAIN
+	PROC
+	 ...		; subroutines used by this test
+
+The PROC part is optional, so the smallest test program looks like:
+
+	TEST 000: null test
+	MAIN 0
+
+The keywords used by "select", like TEST, MAIN, PROC, HOL, OK and ERRLAB,
+all consist of upper case letters and start in column one.
+A convention for test numbers is to use 3 digit numbers, possibly left
+padded with zero's.
+
+A program, called "select", is provided to combine a range of tests
+into a single test program.
+"Select" expects a range as argument, like 0-127, or -127, or 0-.
+Tests that have a TEST number in that range are included.
+"Select" also expects the file from which the tests should
+be selected as an argument.
+If no argument is given, or only a range argument, select expects
+the tests to slect from on standard input.
+
+To prevent name clashes, some rules must be obeyed:
+   - data label names, procedure names and instruction label numbers
+     must be unique over all tests. A good habit is to use the
+     three digit test number as suffix.
+   - only keyword of "select" may start with uppercase letters in column
+     one, to allow for expansion in the future.
+   - because only a single 'hol' pseudo is allowed, "select" must
+     generate the 'hol' pseudo. An individual test may request
+     some 'hol' space by a special HOL line, starting in column one
+     and followed by a single number, the number of bytes needed.
+     This number must consists of digits only, no constant symbols,
+     because "select" must compute the maximum, so before the
+     preprocessor has replaced the constant symbols by their values.
+   - a similar problem is caused by the number of bytes of local
+     storage for 'main'. An individual test may specify the number
+     of bytes it needs as parameter to the MAIN line.
+     Again, the number must consist of digits only.
+
+Test programs print a sequence of integers greater than 1.
+This sequence is terminated by the number 1 as soon as an error is detected.
+If all tests are performed correctedly the number 0 is printed.
+
+To allow test programs to print integers without the full machinery of
+conversion and i/o routines, the EM instruction 'nop' is used.
+Each time this instruction is executed, the current line number as
+maintained by the 'lin' instruction must be printed, followed by a
+newline, at least during debugging.
+
+The following abbrevation may be used in test programs:
+
+	OK	->	lin n
+			nop
+
+Numbers are automatically assigned in order of static appearance.
+As soon as an error is detected you must branch to label 1, by instructions
+like 'bra *1' and 'zne *1'.
+Label 1 is automatically provided in the main routine.
+If you jump to label 1 in a subroutine, then that subroutine must
+end with ERRLAB, like in:
+
+	PROC
+	 pro $test,0
+	 ...
+	 bra *1
+	 ...
+	 ret 0
+	ERRLAB
+	 end
+
+An option to "select" is to generate 'fil' instructions whenever a
+new test starts.
+This is useful if 'nop' prints the 'fil' string as well as the 'lin' number.
+This 'f' option is on by default, off if a '-f' flag is given.
+
+The EM file generated by "select" includes "test.h".
+"test.h" may contain definitions of the following symbols:
+	W2S:	the size of double precision integers, if implemented.
+	FS:	the size of single precision floats, if implemented.
+	F2S:	the size of double precision floats, if implemented.
+The value of these symbols, if defined, must be the size of the object involved.
+
+Two other symbols are used:
+	EM_PSIZE:	pointer size
+	EM_WSIZE:	word size
+The machine dependent translation program, like 8086 and vax2, give
+definitions of these symbols while calling the EM encode program.
+Because these size names occur quite often, they may be abbreviated:
+	WS	->	EM_WSIZE
+	PS	->	EM_PSIZE
+
+Before running the tests in the file "tests", it is wise to test
+the necessary basic functions with some simple tests like
+
+	TEST 000: null
+	MAIN 0
+and
+	TEST 001: ok
+	MAIN 0
+	OK
+and
+	TEST 998: error
+	MAIN 0
+	 bra *1
+and
+	TEST 999: test lni
+	MAIN 0
+	 lin 1
+	 lni
+	 loe 0
+	 loc 2
+	 bne *1
+	OK
+The first two of these are part of "tests" as well. The last two are
+not included in "tests" intensionally, because they would fail.
+The last tests fails because it references the ABS block which is
+inaccessable after an 'hol' pseudo.
+Proceed as follows for each of these basic tests:
+ - make a file called 'basic' containing the test
+ - run select:
+	select basic >basic.e
+ - compile by
+	machine basic.e
+ - and load and run
+
+   where machine should be replaced by the name of program
+   used to compile EM programs for the current machine.

emtest/last

@@ -0,0 +1 @@
+0

emtest/ok

@@ -0,0 +1,10 @@
+trap "" 1 2
+
+while read x
+do
+	case $x in
+	0)	exit 0;;
+	bad)	exit 1;;
+	esac
+done
+exit 1

emtest/select.c

@@ -0,0 +1,249 @@
+/*
+ * (c) copyright 1983 by the Vrije Universiteit, Amsterdam, The Netherlands.
+ *
+ *          This product is part of the Amsterdam Compiler Kit.
+ *
+ * Permission to use, sell, duplicate or disclose this software must be
+ * obtained in writing. Requests for such permissions may be sent to
+ *
+ *      Dr. Andrew S. Tanenbaum
+ *      Wiskundig Seminarium
+ *      Vrije Universiteit
+ *      Postbox 7161
+ *      1007 MC Amsterdam
+ *      The Netherlands
+ *
+ */
+
+#include	<stdio.h>
+#include	<assert.h>
+#include	<signal.h>
+
+#define	LINSIZ	100
+
+int	sigs[] = {
+	SIGHUP,
+	SIGINT,
+	SIGQUIT,
+	SIGTERM,
+	0
+};
+
+char	*prog;
+char	line[LINSIZ];
+int	nlocals	= 0;
+int	nhol	= 0;
+int	nerrors	= 0;
+int	oknum	= 2;
+int	fflag	= 1;
+int	low	= 0;
+int	high	= 999;
+
+FILE	*file1;
+FILE	*file2;
+FILE	*file3;
+char	name1[] = "/usr/tmp/f1XXXXXX";
+char	name2[] = "/usr/tmp/f2XXXXXX";
+char	name3[] = "/usr/tmp/f3XXXXXX";
+
+stop() {
+	unlink(name1);
+	unlink(name2);
+	unlink(name3);
+	exit(nerrors);
+}
+
+main(argc,argv) char **argv; {
+	register *p;
+	register char *s;
+
+	prog = *argv++; --argc;
+	mktemp(name1);
+	mktemp(name2);
+	mktemp(name3);
+	for (p = sigs; *p; p++)
+		if (signal(*p, stop) == SIG_IGN)
+			signal(*p, SIG_IGN);
+	while (argc > 0 && argv[0][0] == '-') {
+		switch (argv[0][1]) {
+		case 'f':
+			fflag ^= 1;
+			break;
+		case '0': case '1': case '2': case '3': case '4':
+		case '5': case '6': case '7': case '8': case '9':
+			high = atoi(&argv[0][1]);
+			break;
+		default:
+			usage();
+			break;
+		}
+		argc--;
+		argv++;
+	}
+	if (argc > 0 && argv[0][0] >= '0' && argv[0][0] <= '9') {
+		s = argv[0];
+		do
+			low = low*10 + *s++ - '0';
+		while (*s >= '0' && *s <= '9');
+		if (*s == 0)
+			high = low;
+		else if (*s++ == '-') {
+			high = atoi(s);
+			if (high == 0)
+				high = 999;
+		} else
+			fatal("bad range %s", argv[0]);
+		argc--;
+		argv++;
+	}
+	if (argc > 1)
+		usage();
+	if (argc == 1 && freopen(argv[0], "r", stdin) == NULL)
+		fatal("cannot open %s", argv[0]);
+	if ((file1 = fopen(name1, "w")) == NULL)
+		fatal("cannot create %s", name1);
+	if ((file2 = fopen(name2, "w")) == NULL)
+		fatal("cannot create %s", name2);
+	if ((file3 = fopen(name3, "w")) == NULL)
+		fatal("cannot create %s", name3);
+	if (getline())
+		while (select())
+			;
+	fclose(file1);
+	fclose(file2);
+	fclose(file3);
+	combine();
+	stop();
+}
+
+select() {
+	register FILE *f;
+	int i;
+
+	if (sscanf(line, "TEST %d", &i) != 1)
+		fatal("bad test identification(%s)", line);
+	if (i < low || i > high) {
+		while (getline())
+			if (line[0] == 'T')
+				return(1);
+		return(0);
+	}
+	fprintf(file2, "; %s\n", line);
+	if (fflag) {
+		fprintf(file1, ".%03d\n", i);
+		fprintf(file1, " con \"tst%03d\"\n", i);
+		fprintf(file2, " fil .%03d\n", i);
+	}
+	f = file1;
+	while (getline()) {
+		switch (line[0]) {
+		case 'T':
+			return(1);
+		case 'M':
+			if (sscanf(line, "MAIN%d", &i) != 1 || i%4 != 0)
+				break;
+			if (i > nlocals)
+				nlocals = i;
+			f = file2;
+			continue;
+		case 'P':
+			if (strcmp(line, "PROC") != 0)
+				break;
+			f = file3;
+			continue;
+		case 'H':
+			if (f != file1 ||
+			    sscanf(line, "HOL%d", &i) != 1 ||
+			    i%4 != 0)
+				break;
+			if (i > nhol)
+				nhol = i;
+			continue;
+		case 'O':
+			if (strcmp(line, "OK") != 0)
+				break;
+			fprintf(f, " lin %d\n nop\n", oknum++);
+			continue;
+		case 'E':
+			if (f != file3 || strcmp(line, "ERRLAB") != 0)
+				break;
+			fprintf(f, "1\n lin 1\n nop\n loc 1\n loc 1\n mon\n");
+			continue;
+		default:
+			putline(f);
+			continue;
+		}
+		fatal("bad line (%s)", line);
+	}
+	return(0);
+}
+
+combine() {
+
+	printf("#define WS EM_WSIZE\n");
+	printf("#define PS EM_PSIZE\n");
+	printf("#include \"test.h\"\n");
+	printf(" mes 2,WS,PS\n");
+	printf(" mes 1\n");
+	printf(" mes 4,300\n");
+	if (nhol)
+		printf(" hol %d,0,0\n", nhol);
+	copy(name1);
+	printf(" exp $m_a_i_n\n");
+	printf(" pro $m_a_i_n,%d\n", nlocals);
+	printf(" loc 123\n");
+	printf(" loc -98\n");
+	copy(name2);
+	printf(" loc -98\n");
+	printf(" bne *1\n");
+	printf(" loc 123\n");
+	printf(" bne *1\n");
+	printf(" lin 0\n");
+	printf(" nop\n");
+	printf(" loc 0\n");
+	printf(" ret WS\n");
+	printf("1\n");
+	printf(" lin 1\n");
+	printf(" nop\n");
+	printf(" loc 1\n");
+	printf(" ret WS\n");
+	printf(" end\n");
+	copy(name3);
+}
+
+copy(s) char *s; {
+	if (freopen(s, "r", stdin) == NULL)
+		fatal("cannot reopen %s", s);
+	while (getline())
+		putline(stdout);
+}
+
+getline() {
+	register len;
+
+	if (fgets(line, LINSIZ, stdin) == NULL)
+		return(0);
+	len = strlen(line);
+	if (line[len-1] != '\n')
+		fatal("line too long(%s)", line);
+	line[len-1] = 0;
+	return(1);
+}
+
+putline(f) FILE *f; {
+	fprintf(f, "%s\n", line);
+}
+
+fatal(s, a1, a2, a3, a4) char *s; {
+	fprintf(stderr, "%s: ", prog);
+	fprintf(stderr, s, a1, a2, a3, a4);
+	fprintf(stderr, " (fatal)\n");
+	nerrors++;
+	stop();
+}
+
+usage() {
+	fprintf(stderr, "usage: %s -f [[low]-[high]] [testcollection]\n", prog);
+	nerrors++;
+	stop();
+}

emtest/test.e

@@ -0,0 +1,28 @@
+#define WS EM_WSIZE
+#define PS EM_PSIZE
+#include "test.h"
+ mes 2,WS,PS
+ mes 1
+ mes 4,300
+.000
+ con "tst000"
+ exp $m_a_i_n
+ pro $m_a_i_n,0
+ loc 123
+ loc -98
+; TEST 000: empty
+ fil .000
+ loc -98
+ bne *1
+ loc 123
+ bne *1
+ lin 0
+ nop
+ loc 0
+ ret WS
+1
+ lin 1
+ nop
+ loc 1
+ ret WS
+ end

etc/Makefile

@@ -0,0 +1,26 @@
+d=..
+h=$d/h
+c=$d/util/data
+
+FILES= \
+$h/em_spec.h \
+$h/em_pseu.h \
+$h/em_mnem.h \
+$c/em_flag.c \
+$c/em_pseu.c \
+$c/em_mnem.c
+
+$(FILES):       em_table
+		new_table $h $c
+
+install:	$(FILES)
+
+opr:
+		make pr ^ opr
+pr:
+		@pr Makefile em_table new_table pop_push traps
+
+clean:
+		-rm -f *.old
+
+cmp :           # do nothing

etc/em_table

@@ -0,0 +1,175 @@
+magic	173
+fmnem	1
+nmnem	149
+fpseu	150
+npseu	30
+filb0	180
+nilb0	60
+fcst0	0
+zcst0	120
+ncst0	240
+fspec	240
+nspec	16
+ilb1	240
+ilb2	241
+dlb1	242
+dlb2	243
+dnam	244
+cst2	245
+cst4	246
+cst8	247
+doff	248
+pnam	249
+scon	250
+icon	251
+ucon	252
+fcon	253
+cend	255
+
+bss	0
+con	1
+end	2
+exa	3
+exc	4
+exp	5
+hol	6
+ina	7
+inp	8
+mes	9
+pro	10
+rom	11
+
+aar	w-	-p-a-p+p
+adf	w-	-a-a+a
+adi	w-	-a-a+a
+adp	f-	-p+p
+ads	w-	-a-p+p
+adu	w-	-a-a+a
+and	w-	-a-a+a
+asp	f-	-a
+ass	w-	-a-x
+beq	bc	-w-w
+bge	bc	-w-w
+bgt	bc	-w-w
+ble	bc	-w-w
+blm	z-	-p-p
+bls	w-	-a-p-p
+blt	bc	-w-w
+bne	bc	-w-w
+bra	bt	0
+cai	-p	-p
+cal	pp	0
+cff	--	-w-w-y+x
+cfi	--	-w-w-y+x
+cfu	--	-w-w-y+x
+cif	--	-w-w-y+x
+cii	--	-w-w-y+x
+ciu	--	-w-w-y+x
+cmf	w-	-a-a+w
+cmi	w-	-a-a+w
+cmp	--	-p-p+w
+cms	w-	-a-a+w
+cmu	w-	-a-a+w
+com	w-	-a-a+a
+csa	wt	-p-a
+csb	wt	-p-a
+cuf	--	-w-w-y+x
+cui	--	-w-w-y+x
+cuu	--	-w-w-y+x
+dch	--	-p+p
+dec	--	-w+w
+dee	g-	0
+del	l-	0
+dup	s-	-a+a+a
+dus	w-	-a-x+x+x
+dvf	w-	-a-a+a
+dvi	w-	-a-a+a
+dvu	w-	-a-a+a
+exg	w-	-a-a+a+a
+fef	w-	-a+a+w
+fif	w-	-a-a+a+a
+fil	g-	0
+gto	gt	-p-?
+inc	--	-w+w
+ine	g-	0
+inl	l-	0
+inn	w-	-w-a+w
+ior	w-	-a-a+a
+lae	g-	+p
+lal	l-	+p
+lar	w-	-p-a-p+?
+ldc	d-	+d
+lde	g-	+d
+ldf	f-	-p+d
+ldl	l-	+d
+lfr	s-	+a
+lil	l-	+w
+lim	--	+w
+lin	n-	0
+lni	--	0
+loc	c-	+w
+loe	g-	+w
+lof	f-	-p+w
+loi	o-	-p+a
+lol	l-	+w
+lor	r-	+p
+los	w-	-a-p+x
+lpb	--	-p+p
+lpi	p-	+p
+lxa	n-	+p
+lxl	n-	+p
+mlf	w-	-a-a+a
+mli	w-	-a-a+a
+mlu	w-	-a-a+a
+mon	--	-?+?
+ngf	w-	-a+a
+ngi	w-	-a+a
+nop	--	0
+rck	w-	-p-a+a
+ret	zt	-a-?
+rmi	w-	-a-a+a
+rmu	w-	-a-a+a
+rol	w-	-w-a+a
+ror	w-	-w-a+a
+rtt	-t	-?
+sar	w-	-p-a-p-?
+sbf	w-	-a-a+a
+sbi	w-	-a-a+a
+sbs	w-	-p-p+a
+sbu	w-	-a-a+a
+sde	g-	-d
+sdf	f-	-p-d
+sdl	l-	-d
+set	w-	-w+a
+sig	--	-p-p+p+p
+sil	l-	-w
+sim	--	-w
+sli	w-	-w-a+a
+slu	w-	-w-a+a
+sri	w-	-w-a+a
+sru	w-	-w-a+a
+ste	g-	-w
+stf	f-	-p-w
+sti	o-	-p-a
+stl	l-	-w
+str	r-	-p
+sts	w-	-a-p-x
+teq	--	-w+w
+tge	--	-w+w
+tgt	--	-w+w
+tle	--	-w+w
+tlt	--	-w+w
+tne	--	-w+w
+trp	-p	-w+?
+xor	w-	-a-a+a
+zeq	bc	-w
+zer	w-	+a
+zge	bc	-w
+zgt	bc	-w
+zle	bc	-w
+zlt	bc	-w
+zne	bc	-w
+zre	g-	0
+zrf	w-	+a
+zrl	l-	0
+

etc/ip_spec.t

@@ -50,7 +50,7 @@ lae 2 120
 lae sw 7 121
 lal P2 128
 lal N2 129
-lal m 1 130
+lal mP 1 130
 lal mN 1 131
 lal swP 1 132
 lal swN 2 133

etc/new_table

@@ -0,0 +1,71 @@
+h=${1-.}
+d=${2-.}
+
+set `grep fpseu em_table`
+p=$2
+set `grep fmnem em_table`
+m=$2
+
+ed - em_table <<'A' > X
+1,/^$/g/	/s// /gp
+A
+
+ed - em_table <<'A' | awk '{print $1,$2+'$p'}' > Y
+1,/^$/d
+1,/^$/g/	/s// /gp
+A
+
+ed - em_table <<'A' | awk '{print $0,'$m'+i++}' > Z
+1,/^$/d
+1,/^$/d
+1,/^$/g/	/s// /gp
+A
+
+i=`wc -l <Y`
+echo 'lpseu' `expr $i + $p - 1` >>X
+i=`wc -l <Z`
+echo 'lmnem' `expr $i + $m - 1` >>X
+
+ed - X <<'A' > $h/em_spec.h
+g/^/s//#define sp_/p
+A
+
+ed - Y <<'A' > $h/em_pseu.h
+g/\(.*\) \(.*\)/s//#define ps_\1 \2/p
+A
+
+ed - Z <<'A' > $h/em_mnem.h
+g/ .* /s// /
+g/\(.*\) \(.*\)/s//#define op_\1 \2/p
+A
+
+(
+echo 'char em_pseu[][4] = {'
+ed - Y <<'A'
+g/\(...\).*/s//	"\1",/p
+A
+echo '};'
+) > $d/em_pseu.c
+
+(
+echo 'char em_mnem[][4] = {'
+ed - Z <<'A'
+g/\(...\).*/s//	"\1",/p
+A
+echo '};'
+) > $d/em_mnem.c
+
+(
+echo '#include	<em_flag.h>
+char em_flag[] = {'
+ed - Z <<'A' | tr a-z A-Z
+g/^... /s///
+g/ .*/s///
+g/\(.\)\(.\)/s//PAR_\1 | FLO_\2/
+g/-/s//NO/g
+g/.*/s//	&,/p
+A
+echo '};'
+) > $d/em_flag.c
+
+rm X Y Z

etc/pc_errors

@@ -0,0 +1,289 @@
+non-standard feature used
+identifier '%s' declared twice
+end of file encountered
+bad line directive
+unsigned real: digit of fraction expected
+unsigned real: digit of exponent expected
+unsigned real: too many digits (>72)
+unsigned integer: too many digits (>72)
+unsigned integer: overflow (>32767)
+string constant: must not exceed one line
+string constant: at least one character expected
+string constant: double quotes not allowed (see c option)
+string constant: too long (>72 chars)
+bad character
+identifier '%s' not declared
+location counter overflow: arrays too big
+location counter overflow: arrays too big
+arraysize too big
+variable '%s' never used
+variable '%s' never assigned
+the files contained in '%s' are not closed automatically
+constant expected
+constant: only integers and reals may be signed
+constant: out of bounds
+simple type expected
+enumerated type: element identifier expected
+enumerated type: ',' or ')' expected
+enumerated type: ',' expected
+enumerated type: ')' expected
+subrange type: type must be scalar, but not real
+subrange type: '..' expected
+subrange type: type of lower and upper bound incompatible
+subrange type: lower bound exceeds upper bound
+array type: '[' expected
+conformant array: low bound identifier expected
+conformant array: '..' expected
+conformant array: high bound identifier expected
+conformant array: ':' expected
+conformant array: index type identifier expected
+array type: index type not bounded
+array type: index separator or ']' expected
+array type: index separator expected
+array type: ']' expected
+array type: 'of' expected
+record variant part: tag type identifier expected
+record variant part: tag type identifier expected
+record variant part: type must be bounded
+record variant part: 'of' expected
+record variant: type of case label and tag incompatible
+record variant: multiple defined case label
+record variant: ',' or ':' expected
+record variant: ',' expected
+record variant: ':' expected
+record variant: '(' expected
+record variant: ')' expected
+record variant part: ';' or end of variant list expected
+record variant part: ';' expected
+record variant part: end of variant list expected
+record variant part: there must be a variant for each tag value
+field list: record section expected
+record section: field identifier expected
+record section: ',' or ':' expected
+record section: ',' expected
+record section: ':' expected
+field list: ';' or end of record section list expected
+field list: ';' expected
+field list: end of record section list expected
+type expected
+type: simple and pointer type may not be packed
+pointer type: type identifier expected
+pointer type: type identifier expected
+record type: 'end' expected
+set type: 'of' expected
+set type: too many elements in set
+set type: bad subrange of integer
+set of integer: the i option dictates the number of bits (default 16)
+set type: base type not bounded
+file type: 'of' expected
+file type: files within files not allowed
+var parameter: type identifier or conformant array expected
+var parameter: type identifier expected
+label declaration: unsigned integer expected
+label declaration: label '%i' multiple declared
+label declaration: ',' or ';' expected
+label declaration: ',' expected
+label declaration: ';' expected
+const declaration: constant identifier expected
+const declaration: '=' expected
+const declaration: ';' expected
+const declaration: constant identifier or 'type', 'var', 'procedure', 'function' or 'begin' expected
+type declaration: type identifier expected
+type declaration: '=' expected
+type declaration: ';' expected
+type declaration: type identifier or 'var', 'procedure', 'function' or 'begin' expected
+var declaration: var identifier expected
+var declaration: ',' or ':' expected
+var declaration: ',' expected
+var declaration: ':' expected
+var declaration: ';' expected
+var declaration: var identifier or 'procedure', 'function' or 'begin' expected
+parameter list: 'var','procedure','function' or identifier expected
+parameter list: parameter identifier expected
+parameter list: ',' or ':' expected
+parameter list: ',' expected
+parameter list: ':' expected
+parameter list: type identifier expected
+parameter list: ';' or ')' expected
+parameter list: ';' expected
+proc/func declaration: proc/func identifier expected
+proc/func declaration: previous declaration of '%s' was not forward
+proc/func declaration: parameter list expected
+parameterlist: ')' expected
+func declaration: ':' expected
+func declaration: result type identifier expected
+func declaration: result type must be scalar, subrange or pointer
+proc/func declaration: ';' expected
+proc/func declaration: block or directive expected
+proc/func declaration: '%s' unknown directive
+proc/func declaration: '%s' again forward declared
+proc/func declaration: ';' expected
+indexed variable: '[' only allowed following array variables
+indexed variable: index type not compatible with declaration
+indexed variable: ',' or ']' expected
+indexed variable: ',' expected
+assignment: standard function not allowed as destination
+assignment: cannot store the function result
+assignment: formal parameter function not allowed as destination
+assignment: function identifier may not be de-referenced
+variable: '[', '.', '^' or end of variable expected
+indexed variable: ']' expected
+field designator: field identifier expected
+field designator: '.' only allowed following record variables
+field designator: no field '%s' in this record
+referenced variable: '^' not allowed following zero-terminated strings
+referenced variable: '^' only allowed following pointer or file variables
+variable: var or field identifier expected
+call: too many actual parameters supplied
+call: proc/func identifier expected
+call: standard proc/func may not be used as parameter
+call: parameter lists of actual and formal proc/func incompatible
+call: type of actual and formal value parameter not compatible
+call: array parameter not conformable
+call: type of actual and formal variable parameter not similar
+call: packed elements not allowed as variable parameter
+call: ',' or ')' expected
+call: too few actual parameters supplied
+read(ln): type must be integer, char or real
+write(ln): type must be integer, char, real, string or boolean
+write(ln): ':', ',' or ')' expected
+write(ln): field width must be integer
+write(ln): ':', ',' or ')' expected
+write(ln): precision must be integer
+write(ln): precision may only be specified for reals
+read/write: too few actual parameters supplied
+read/write: standard input/output not mentioned in program heading
+read/write: ',' or ')' expected
+read/write: type of parameter not the same as that of the file elements
+read/write: parameter list expected
+readln/writeln: standard input/output not mentioned in program heading
+readln/writeln: only allowed on text files
+new/dispose: C-type strings not allowed here
+new/dispose: ',' or ')' expected
+new/dispose: too many actual parameters supplied
+new/dispose: type of tagfield value is incompatible with declaration
+call: '(' or end of call expected
+standard proc/func: parameter list expected
+standard input/output not mentioned in program heading
+file variable expected
+pointer variable expected
+pack: ',' expected
+pack: ',' expected
+unpack: ',' expected
+unpack: ',' expected
+standard proc/func: parameter type incompatible with specification
+eoln/page: text file variable expected
+pack/unpack: array types are incompatible
+pack/unpack: only for arrays
+abs: integer or real expected
+sqr: integer or real expected
+ord: type must be scalar or subrange, but not real
+pred/succ: type must be scalar or subrange, but not real
+trunc/round: real argument required
+call: ')' expected
+expression: left and right operand are incompatible
+set: incompatible elements
+set: base type must be bounded or of type integer
+set: base type upper bound exceeds maximum set element number
+set: element out of range
+set: ']' or element list expected
+set: '..', ',' or ']' expected
+set: ',' or ']' expected
+set: ',' expected
+factor expected
+factor: ')' expected
+factor: type of factor must be boolean
+set: ']' expected
+term: multiplying operator or end of term expected
+term: '*' only defined for integers, reals and sets
+term: '/' only defined for integers and reals
+term: 'div' only defined for integers
+term: 'mod' only defined for integers
+term: 'and' only defined for booleans
+simple expression: only integers and reals may be signed
+simple expression: adding operator or end of simple expression expected
+simple expression: '+' only defined for integers, reals and sets
+simple expression: '-' only defined for integers, reals and sets
+simple expression: 'or' only defined for booleans
+expression: relational operator or end of expression expected
+expression: set expected
+expression: left operand of 'in' not compatible with base type of right operand
+expression: only '=' and '<>' allowed on pointers
+expression: '<' and '>' not allowed on sets
+expression: comparison of arrays only allowed for strings
+expression: comparison of records not allowed
+expression: comparison of files not allowed
+assignment: ':=' expected
+assignment: left and right hand side incompatible
+goto statement: unsigned integer expected
+goto statement: label '%i' not declared
+if statement: type of expression must be boolean
+if statement: 'then' expected
+if statement: 'else' or end of if statement expected
+case statement: type must be scalar or subrange, but not real
+case statement: 'of' expected
+case statement: incompatible case label
+case statement: multiple defined case label
+case statement: ',' or ':' expected
+case statement: ',' expected
+case statement: ':' expected
+case statement: ';' or 'end' expected
+case statement: ';' expected
+case statement: 'end' expected
+repeat statement: ';' or 'until' expected
+repeat statement: ';' expected
+repeat statement: 'until' expected
+repeat statement: type of expression must be boolean
+while statement: type of expression must be boolean
+while statement: 'do' expected
+for statement: type of bound and control variable incompatible
+for statement: control variable expected
+for statement: control variable must be local
+for statement: type must be scalar or subrange, but not real
+for statement: ':=' expected
+for statement: 'to' or 'downto' expected
+for statement: upper bound not assignment compatible
+for statement: 'do' expected
+with statement: record variable expected
+with statement: ',' or 'do' expected
+with statement: ',' expected
+with statement: 'do' expected
+assertion: type of expression must be boolean
+statement expected
+label '%i' not declared
+label '%i' multiple defined
+statement: ':' expected
+unlabeled statement expected
+compound statement: ';' or 'end' expected
+compound statement: ';' expected
+compound statement: 'end' expected
+case statement: 'end' expected
+body: ';' or 'end' expected
+body: ';' expected
+body: label '%i' declared, but never defined
+program parameter '%s' not declared
+function '%s' never assigned
+block: declaration or body expected
+block: 'const', 'type', 'var', 'procedure', 'function' or 'begin' expected
+block: 'type', 'var', 'procedure', 'function' or 'begin' expected
+block: 'var', 'procedure', 'function' or 'begin' expected
+block: 'procedure', 'function' or 'begin' expected
+block: unsatisfied forward proc/func declaration(s)
+block: 'begin' expected
+block: 'end' expected
+program heading: 'program' expected
+program heading: program identifier expected
+program heading: file identifier list expected
+program heading: file identifier expected
+program heading: ',' or ')' expected
+program heading: ',' expected
+program heading: maximum number of file arguments exceeded (12)
+program heading: ')' expected
+program heading: ';' expected
+program: '.' expected
+'program' expected
+module: 'const', 'type', 'var', 'procedure' or 'function' expected
+module: 'type', 'var', 'procedure' or 'function' expected
+module: 'var', 'procedure' or 'function' expected
+module: 'procedure' or 'function' expected
+garbage at end of program

etc/pc_rt_errors

@@ -0,0 +1,107 @@
+array bound error
+range bound error
+set bound error
+integer overflow
+real overflow
+real underflow
+divide by 0
+divide by 0.0
+undefined integer
+real undefined
+conversion error
+error 11
+error 12
+error 13
+error 14
+error 15
+stack overflow
+heap error
+illegal instruction
+odd or zero byte count
+case error
+memory fault
+bad pointer
+bad program counter
+bad external address
+bad monitor call
+bad line number
+error 27
+error 28
+error 29
+error 30
+error 31
+error 32
+error 33
+error 34
+error 35
+error 36
+error 37
+error 38
+error 39
+error 40
+error 41
+error 42
+error 43
+error 44
+error 45
+error 46
+error 47
+error 48
+error 49
+error 50
+error 51
+error 52
+error 53
+error 54
+error 55
+error 56
+error 57
+error 58
+error 59
+error 60
+error 61
+error 62
+error 63
+more args expected
+error in exp
+error in ln
+error in sqrt
+assertion failed
+array bound error in pack
+array bound error in unpack
+only positive j in 'i mod j'
+file not yet open
+dispose error
+error 74
+error 75
+error 76
+error 77
+error 78
+error 79
+error 80
+error 81
+error 82
+error 83
+error 84
+error 85
+error 86
+error 87
+error 88
+error 89
+error 90
+error 91
+error 92
+error 93
+error 94
+error 95
+not writable
+not readable
+end of file
+truncated
+reset error
+rewrite error
+close error
+read error
+write error
+digit expected
+non-ASCII char read

etc/pop_push

@@ -0,0 +1,15 @@
+description of third column of em_table:
+
+	-: pop item indicated by next character
+	+: push item indicated by next character
+	0: no effect on the stack
+
+characters describing items:
+
+	w: target machine word (1, 2 or 4)
+	d: double target machine word (2, 4 or 8)
+	p: target machine address
+	a: item with size specified in argument
+	x: item with size specified by top item of stack
+	y: item with size specified by second item on stack
+	?: one or more items of unknown size

etc/traps

@@ -0,0 +1,28 @@
+~ Array bound error
+~ Range bound error
+~ Set bound error
+~ Integer overflow
+~ Floating overflow
+~ Floating underflow
+~ Divide by 0
+~ Divide by 0.0
+~ Integer undefined
+~ Floating undefined
+~ Conversion error
+
+
+
+
+
+* Stack overflow
+* Heap overflow
+* Illegal instruction
+* Illegal odd or zero argument
+* Case error
+* Addressing non existent memory
+* Bad pointer used
+* Program counter out of range
+* Bad argument of LAE
+* Bad monitor call
+* Argument of LIN too high
+* Bad GTO descriptor

first/ckpath

@@ -0,0 +1,32 @@
+rm -f ../bin/x_tpath x_tpath
+echo "echo $$" >../bin/x_tpath
+rm -f x_tpath
+chmod +x ../bin/x_tpath
+case x`(x_tpath) 2>/dev/null`
+in
+x$$)	
+	STAT=0 ;;
+x)
+	(cd ../bin ; echo Sorry, `pwd` is not in your shell PATH" ($PATH)")
+	STAT=1 ;;
+*)
+	echo "Sorry, there is something wrong with your PATH ($PATH)" ;;
+esac
+echo "echo l_$$" >x_tpath
+chmod +x x_tpath
+case x`(x_tpath) 2>/dev/null`
+in
+xl_$$)
+	;;
+x)
+	(cd ../bin ; echo Sorry, . is not in your shell PATH" ($PATH)")
+	STAT=2 ;;
+x$$)	
+	echo Sorry, . is not in your PATH" ($PATH)" or after the ACK bin directory
+	STAT=3 ;;
+*)
+	echo "Sorry, there is something wrong with your PATH ($PATH)"
+	STAT=4 ;;
+esac
+rm -f ../bin/x_tpath x_tpath
+exit $STAT

first/did_first

@@ -0,0 +1,7 @@
+if (ack_sys ) >/dev/null 2>&1
+then
+	exit 0
+else
+	echo "You need to run 'first' first"
+	exit 1
+fi

first/em_path.h.src

@@ -0,0 +1,7 @@
+/* Intended as a common directory for ALL temporary files */
+#define TMP_DIR		"/usr/tmp"
+
+/* Access to the ACK tree and parts thereof */
+#define EM_DIR		"/usr/em"	/* The root directory for EM stuff */
+#define RTERR_PATH	"etc/pc_rt_errors"
+#define ACK_PATH	"lib/descr"

first/first

@@ -0,0 +1,146 @@
+: check $PATH first
+if sh ckpath
+then :
+else
+	exit 1
+fi
+: check write-ability of /tmp and /usr/tmp
+if ( >/usr/tmp/aaax.$$ )
+then
+	rm /usr/tmp/aaax.$$
+else
+	echo /usr/tmp must exist and be writable.
+	exit 2
+fi
+if ( >/tmp/aaax.$$ )
+then
+	rm /tmp/aaax.$$
+else
+	echo /tmp must exist and be writable.
+	exit 2
+fi
+: set ACK HOME Directory in ../h/em_path.h
+rm -f em_path.h
+sed -e "/^#define[ 	]*EM_DIR/s@\".*\"@\"`cd .. ; pwd`\"@" <../h/em_path.h >em_path.h
+if cmp ../h/em_path.h em_path.h >/dev/null 2>&1
+then
+	: Don't touch ../h/em_path.h, it's already correct
+else
+	rm -f ../h/em_path.h
+	if mv em_path.h ../h >/dev/null 2>&1
+	then : success
+	else
+		echo "Sorry, can't replace ../h/em_path.h"
+		exit 7
+	fi
+fi
+: remove non-system as and ld from descr files
+if (ack_sys) >/dev/null 2>&1
+then
+	: echo Your system is: `ack_sys`.
+else
+	echo -n "Give me the type of your system, the current choice is:
+pdp_v7		PDP11 with sep I/D and version 7
+vax_bsd4_1a	VAX11 with BSD4.1a
+vax_bsd4_1c	VAX11 with BSD4.1c
+vax_bsd4_2	VAX11 with BSD4.2
+pc_ix		IBM PC with PC/IX
+m68_unisoft	Motorola 68000 with Unisoft UNIX
+ANY		Neither of the above
+
+system type: "
+	if read SYSNAME
+	then
+		echo echo "$SYSNAME" >../bin/ack_sys
+		chmod +x ../bin/ack_sys
+		case `ack_sys` in
+		pdp_v7|vax_bsd4_1[ac]|vax_bsd4_2|pc_ix|m68_unisoft) ;;
+		*)	echo None of the software especially intended for the named systems will work ;;
+		esac
+	else
+		echo Sorry, got EOF when reading system name.
+		exit 8
+	fi
+fi
+echo -n "Your system is `ack_sys`, are you satisfied with that? (y/n) "
+if read YESNO
+then
+	case $YESNO in
+	j*|y*)	;;
+	n*)	echo Ok, I will give you another chance....
+		rm -f ../bin/ack_sys
+		exec sh $0
+		;;
+	*)	echo "I do not understand your answer ($YESNO). Bye"
+		exit 9
+		;;
+	esac
+else
+	echo Sorry, got EOF when reading your answer.
+	exit 9
+fi
+: "Take action according to the system used"
+: 'Prevent the use of the system assembler on for certain systems'
+case `ack_sys` in
+vax_bsd*)	RMD=pdp ;;
+pdp_*)		RMD="vax2 vax4" ;;
+*)		RMD="pdp vax2 vax4" ;;
+esac
+for i in $RMD
+do
+(	cd ../lib/$i
+	if grep '^name as$' descr >/dev/null 2>&1
+		then
+cp descr descr.orig
+ed - descr <<'ABC'
+/^name as$/;/^end$/d
+/^name ld$/;/^end$/d
+w
+q
+ABC
+	fi
+)
+done
+: 'Set the default machine in ../h/local.h'
+case `ack_sys` in
+pdp_v7)		ACM=pdp ;;
+vax_bsd4_1[ac]) ACM=vax2 ;;
+vax_bsd4_2)	ACM=vax2 ;;
+pc_ix)		ACM=ix ;;
+m68_unisoft)	ACM=m68k2 ;;
+*)		ACM=m68k2 ;;
+esac
+rm -f local.h
+sed /ACKM/s/'".*"'/'"'$ACM'"'/ <../h/local.h >local.h
+if cmp -s ../h/local.h local.h
+then :
+else
+	cp local.h ../h
+	rm -f local.h
+fi
+echo "Your default machine to compile for is $ACM"
+case `ack_sys` in
+vax_bsd4_*)
+	echo 'Installing the include directory in lib/vax2'
+	( cd ../lib/vax2 ; sh fetch_inc )
+	echo Done
+	case `ack_sys` in
+	vax_bsd4_1a)	VERS=BSD41a ;;
+	vax_bsd4_1c)	VERS=BSD41c ;;
+	vax_bsd4_2)	VERS=BSD42 ;;
+	*)		echo "Unknown VAX BSD version, look at mach/vax[24]/libem"
+			break ;;
+	esac
+	for i in vax2 vax4
+	do (
+		cd ../mach/$i/libem
+		ed - system.h <<ABC
+g/^#/s/.*/\/* & *\//
+/$VERS/s/^.*#/#/
+/$VERS/s/*\/.*$//
+w
+q
+ABC
+	) done
+	echo 'mach/vax[24]/libem/system.h reflects your BSD version.'
+esac

first/local.h.src

@@ -0,0 +1,7 @@
+/* collection of options, selected by including or excluding 'defines' */
+
+/* Version number of the EM object code */
+#	define	VERSION		3	/* 16 bits number */
+
+/* The default machine used by ack, acc, apc */
+#	define	ACKM		"pdp"

h/Makefile

@@ -0,0 +1,10 @@
+install cmp:
+
+opr:
+	make pr | opr
+
+pr:
+	@pr Makefile *.h
+
+clean:
+	-rm -f *.old

h/arch.h

@@ -0,0 +1,12 @@
+#define	ARMAG	0177545
+struct	ar_hdr {
+	char	ar_name[14];
+	long	ar_date;
+	char	ar_uid;
+	char	ar_gid;
+	int	ar_mode;
+	long	ar_size;
+};
+
+#define AR_TOTAL	26
+#define AR_SIZE		22

h/as_spec.h

@@ -0,0 +1 @@
+#define as_magic        (sp_magic|(14<<8))

h/bc_io.h

@@ -0,0 +1,29 @@
+#include <stdio.h>
+
+/* $Header$ */
+
+/* BASIC file io definitions */
+
+extern FILE *_chanrd;
+extern FILE *_chanwr;
+extern int   _chann;
+/* BASIC file descriptor table */
+/* Channel assignment:
+   -1		terminal IO
+    0		data file
+    1-15	user files
+*/
+
+/* FILE MODES:*/
+#define 	IMODE	1
+#define		OMODE	2
+#define		RMODE	3
+
+typedef struct {
+	char	*fname;
+	FILE	*fd;
+	int	pos;
+	int	mode;	
+	int	reclength;
+	}Filedesc;
+extern Filedesc	 _fdtable[16];

h/bc_string.h

@@ -0,0 +1,17 @@
+#
+
+/* $Header$ */
+
+/* Strings are allocated in a fixed string descriptor table 
+** This mechanism is used to avoid string copying as much as possible
+*/
+
+typedef struct{
+	char	*strval;
+	int	strcount;
+	int	strlength;
+	} String;
+
+String *_newstr() ;
+
+#define MAXSTRING 1024

h/cg_pattern.h

@@ -0,0 +1,156 @@
+/* offsets of interesting fields in EM-pattern */
+
+#define PO_HASH         0
+#define PO_NEXT         1
+#define PO_MATCH        3
+
+#define ILLHASH 0177777
+
+/* Escapes in printstrings */
+
+#define PR_TOK          '\001'
+#define PR_TOKFLD       '\002'
+#define PR_EMINT        '\003'
+#define PR_EMSTR        '\004'
+#define PR_ALLREG       '\005'
+#define PR_SUBREG       '\006'
+/*
+ * In case this list gets longer remember to keep out printable nonprintables
+ * like \t \n \r and the like.
+ */
+
+/* Commands for codegenerator, in low order 5 bits of byte */
+
+#define DO_NEXTEM       0
+#define DO_MATCH        1
+#define DO_XMATCH	2
+#define DO_XXMATCH	3
+#define DO_REMOVE       4
+#define DO_DEALLOCATE   5
+#define DO_REALLOCATE   6
+#define DO_ALLOCATE     7
+#define DO_LOUTPUT      8
+#define DO_ROUTPUT      9
+#define DO_MOVE         10
+#define DO_ERASE        11
+#define DO_TOKREPLACE   12
+#define DO_EMREPLACE    13
+#define DO_COST         14
+#define DO_RETURN       15
+#define DO_COERC        16
+#define DO_PRETURN	17
+#define DO_RREMOVE	18
+
+typedef struct instance {
+	int in_which;
+#               define IN_COPY          1
+#               define IN_RIDENT        2
+#               define IN_ALLOC         3
+#               define IN_DESCR         4
+#		define IN_REGVAR	5
+	int in_info[TOKENSIZE+1];
+} inst_t,*inst_p;
+
+typedef struct {
+	int     c_size;                 /* index in enode-table */
+	int     c_time;                 /* dito */
+} cost_t,*cost_p;
+
+typedef struct {
+	int m_set1;             /* number of tokenexpr in move: from */
+	int m_expr1;            /* optional expression */
+	int m_set2;             /* number of tokenexpr in move: to */
+	int m_expr2;            /* optional expression */
+	int m_cindex;           /* code index to really do it */
+	cost_t m_cost;          /* associated cost */
+} move_t, *move_p;
+
+typedef struct {
+	int set_size;
+	short set_val[SETSIZE];
+} set_t,*set_p;
+
+struct exprnode {
+	short ex_operator;
+	short ex_lnode;
+	short ex_rnode;
+};
+typedef struct exprnode node_t;
+typedef struct exprnode *node_p;
+
+typedef struct {        /* to stack coercions */
+	int c1_texpno;          /* token expression number */
+	int c1_expr;		/* boolean expression */
+	int c1_prop;		/* property of register needed */
+	int c1_codep;           /* code index */
+	cost_t c1_cost;		/* cost involved */
+} c1_t,*c1_p;
+
+#ifdef MAXSPLIT
+typedef struct {        /* splitting coercions */
+	int c2_texpno;          /* token expression number */
+	int c2_nsplit;          /* split factor */
+	int c2_repl[MAXSPLIT];  /* replacement instances */
+	int c2_codep;           /* code index */
+} c2_t,*c2_p;
+#endif MAXSPLIT
+
+typedef struct {        /* one to one coercions */
+	int c3_texpno;          /* token expression number */
+	int c3_prop;            /* property of register needed */
+	int c3_repl;            /* replacement instance */
+	int c3_codep;           /* code index */
+} c3_t,*c3_p;
+
+/*
+ * contents of .ex_operator
+ */
+
+#define EX_TOKFIELD     0
+#define EX_ARG          1
+#define EX_CON          2
+#define EX_ALLREG       3
+#define EX_SAMESIGN     4
+#define EX_SFIT         5
+#define EX_UFIT         6
+#define EX_ROM          7
+#define EX_NCPEQ        8
+#define EX_SCPEQ        9
+#define EX_RCPEQ        10
+#define EX_NCPNE        11
+#define EX_SCPNE        12
+#define EX_RCPNE        13
+#define EX_NCPGT        14
+#define EX_NCPGE        15
+#define EX_NCPLT        16
+#define EX_NCPLE        17
+#define EX_OR2          18
+#define EX_AND2         19
+#define EX_PLUS         20
+#define EX_CAT          21
+#define EX_MINUS        22
+#define EX_TIMES        23
+#define EX_DIVIDE       24
+#define EX_MOD          25
+#define EX_LSHIFT       26
+#define EX_RSHIFT       27
+#define EX_NOT          28
+#define EX_COMP         29
+#define EX_COST         30
+#define EX_STRING       31
+#define EX_DEFINED      32
+#define EX_SUBREG       33
+#define EX_TOSTRING     34
+#define EX_UMINUS       35
+#define EX_REG          36
+#define EX_LOWW		37
+#define EX_HIGHW	38
+#define EX_INREG	39
+#define EX_REGVAR	40
+
+
+
+#define getint(a,b) \
+	if ((a=((*(b)++)&BMASK)) >= 128) {\
+		a = ((a-128)<<BSHIFT) | (*(b)++&BMASK); \
+	}

h/cgg_cg.h

@@ -0,0 +1,154 @@
+/* $Header$ */
+
+/* offsets of interesting fields in EM-pattern */
+
+#define PO_HASH         0
+#define PO_NEXT         1
+#define PO_MATCH        3
+
+#define ILLHASH 0177777
+
+
+/* Commands for codegenerator, in low order 5 bits of byte */
+
+#define DO_NEXTEM       0
+#define DO_MATCH        1
+#define DO_XMATCH	2
+#define DO_XXMATCH	3
+#define DO_REMOVE       4
+#define DO_DEALLOCATE   5
+#define DO_REALLOCATE   6
+#define DO_ALLOCATE     7
+#define DO_MOVE         10
+#define DO_ERASE        11
+#define DO_TOKREPLACE   12
+#define DO_EMREPLACE    13
+#define DO_COST         14
+#define DO_RETURN       15
+#define DO_COERC        16
+#define DO_PRETURN	17
+#define DO_RREMOVE	18
+#define DO_INSTR	19
+#define DO_TEST		20
+#define DO_DLINE	21
+#define DO_SETCC	22
+
+#ifndef MAXATT
+#define MAXATT TOKENSIZE
+#endif
+
+typedef struct instance {
+	short in_which;
+#               define IN_COPY          1
+#		define IN_MEMB		2
+#               define IN_RIDENT        3
+#               define IN_ALLOC         4
+#               define IN_DESCR         5
+#               define IN_S_DESCR       6
+#               define IN_D_DESCR       7
+	short in_info[MAXATT+1];
+} inst_t,*inst_p;
+
+typedef struct set {
+	short set_size;
+	short set_val[SETSIZE];
+} set_t,*set_p;
+
+typedef struct {
+	short m_set1;           /* number of tokenexpr in move: from */
+	short m_expr1;          /* optional expression */
+	short m_set2;           /* number of tokenexpr in move: to */
+	short m_expr2;          /* optional expression */
+	short m_cindex;         /* code index to really do it */
+} move_t, *move_p;
+
+typedef struct {
+	short t_set;		/* number of tokenexpr in test */
+	short t_expr;		/* optional expression */
+	short t_cindex;		/* code index to really do it */
+} test_t, *test_p;
+
+struct exprnode {
+	short ex_operator;
+	short ex_lnode;
+	short ex_rnode;
+};
+typedef struct exprnode node_t;
+typedef struct exprnode *node_p;
+
+/*
+ * contents of .ex_operator
+ */
+
+#define EX_TOKFIELD     0
+#define EX_ARG          1
+#define EX_CON          2
+#define EX_ALLREG       3
+#define EX_SAMESIGN     4
+#define EX_SFIT         5
+#define EX_UFIT         6
+#define EX_ROM          7
+#define EX_NCPEQ        8
+#define EX_SCPEQ        9
+#define EX_RCPEQ        10
+#define EX_NCPNE        11
+#define EX_SCPNE        12
+#define EX_RCPNE        13
+#define EX_NCPGT        14
+#define EX_NCPGE        15
+#define EX_NCPLT        16
+#define EX_NCPLE        17
+#define EX_OR2          18
+#define EX_AND2         19
+#define EX_PLUS         20
+#define EX_CAT          21
+#define EX_MINUS        22
+#define EX_TIMES        23
+#define EX_DIVIDE       24
+#define EX_MOD          25
+#define EX_LSHIFT       26
+#define EX_RSHIFT       27
+#define EX_NOT          28
+#define EX_COMP         29
+#define EX_STRING       31
+#define EX_DEFINED      32
+#define EX_SUBREG       33
+#define EX_TOSTRING     34
+#define EX_UMINUS       35
+#define EX_REG          36
+#define EX_LOWW		37
+#define EX_HIGHW	38
+#define EX_INREG	39
+#define EX_REGVAR	40
+
+
+typedef struct {        /* to stack coercions */
+	short c1_texpno;        /* token expression number */
+	short c1_expr;		/* boolean expression */
+	short c1_prop;		/* property of register needed */
+	short c1_codep;         /* code index */
+} c1_t,*c1_p;
+
+#ifdef MAXSPLIT
+typedef struct {        /* splitting coercions */
+	short c2_texpno;        /* token expression number */
+	short c2_expr;		/* optional boolean expression */
+	short c2_nsplit;        /* split factor */
+	short c2_repl[MAXSPLIT];/* replacement instances */
+	short c2_codep;         /* code index */
+} c2_t,*c2_p;
+#endif MAXSPLIT
+
+typedef struct {        /* one to one coercions */
+	short c3_texpno;        /* token expression number */
+	short c3_expr;		/* boolean expression */
+	short c3_prop;          /* property of register needed */
+	short c3_repl;          /* replacement instance */
+	short c3_codep;         /* code index */
+} c3_t,*c3_p;
+
+
+#define getint(a,b) \
+	if ((a=((*(b)++)&BMASK)) >= 128) {\
+		a = ((a-128)<<BSHIFT) | (*(b)++&BMASK); \
+	}

h/em_abs.h

@@ -0,0 +1,30 @@
+#define LINO_AD         0
+#define FILN_AD         4
+
+#define LINO            (*(int    *)(_hol0()+LINO_AD))
+#define FILN            (*(char  **)(_hol0()+FILN_AD))
+
+#define EARRAY          0
+#define ERANGE          1
+#define ESET            2
+#define EIOVFL          3
+#define EFOVFL          4
+#define EFUNFL          5
+#define EIDIVZ          6
+#define EFDIVZ          7
+#define EIUND           8
+#define EFUND           9
+#define ECONV           10
+
+#define ESTACK          16
+#define EHEAP           17
+#define EILLINS         18
+#define EODDZ           19
+#define ECASE           20
+#define EMEMFLT         21
+#define EBADPTR         22
+#define EBADPC          23
+#define EBADLAE         24
+#define EBADMON         25
+#define EBADLIN         26
+#define EBADGTO         27

h/em_ego.h

@@ -0,0 +1,12 @@
+/*
+ * The various different hints as given after a mes ms_ego
+ *
+ * Yet to be stabilized
+ */
+
+#define ego_live    0	/* ,offset,size,regno */
+#define ego_dead    1	/* ,offset,size,regno */
+#define ego_assoc   2	/* ,offset,size,regno */
+#define ego_unass   3	/* ,offset,size,regno */
+#define ego_init    4	/* ,offset,size,regno */
+#define ego_update  5	/* ,offset,size,regno */

h/em_flag.h

@@ -0,0 +1,25 @@
+/* flags */
+#define	EM_PAR	0017	/* parameter type */
+#define	EM_FLO	0060	/* flow information */
+
+/* types */
+#define PAR_NO	0000	/* no parameter */
+#define PAR_C	0001	/* constant */
+#define PAR_D	0002	/* double word constant */
+#define PAR_N	0003	/* numeric (>=0) */
+#define PAR_F	0004	/* address offset */
+#define PAR_L	0005	/* addressing locals/parameters */
+#define PAR_G	0006	/* addressing globals */
+#define	PAR_W	0007	/* size: word multiple, fits word, possibly indirect */
+#define PAR_S	0010	/* size: word multiple */
+#define PAR_Z	0011	/* size: zero or word multiple */
+#define PAR_O	0012	/* size: word multiple or word fraction */
+#define PAR_P	0013	/* procedure name */
+#define PAR_B	0014	/* branch: instruction label */
+#define PAR_R	0015	/* register number (0,1,2) */
+
+/* flow */
+#define	FLO_NO	0000	/* straight on */
+#define	FLO_C	0020	/* conditional branch */
+#define	FLO_P	0040	/* procedure: call and return */
+#define	FLO_T	0060	/* terminate: no return */

h/em_mes.h

@@ -0,0 +1,21 @@
+/*
+ * mnemonics for the message numbers in EM
+ */
+
+#define	ms_err	 0	/* Compilation error occurred, ignore rest of module */
+#define	ms_opt	 1	/* Disable optimization please                       */
+#define	ms_emx	 2	/* Wordsize and pointersize assumed                  */
+#define	ms_reg	 3	/* Hint for possible register usage from frontend    */
+#define	ms_src	 4	/* Number of source lines in this module             */
+#define	ms_flt	 5	/* Floating point used                               */
+#define	ms_com	 6	/* Comment to be retained in compact code            */
+#define	ms_ret	 7	/* Reserved                                          */
+#define ms_ext	 8	/* List of exported symbols from this library module */
+#define ms_par	 9	/* Number of bytes of parameters accessed            */
+#define ms_ego	10	/* Hint from EM Global Optimizer                     */
+#define ms_gto	11	/* Dangerous procedure, uses nonlocal goto	     */
+
+/*
+ * for details about ms_reg, see em_reg.h
+ * for details about ms_ego, see em_ego.h
+ */

h/em_ptyp.h

@@ -0,0 +1,8 @@
+#define	ptyp(x)		(1<<(x-sp_fspec))
+
+#define	cst_ptyp	0000140
+#define	sym_ptyp	0000034
+#define	arg_ptyp	0000574
+#define	con_ptyp	0036000
+#define	val_ptyp	0037777
+#define	any_ptyp	0137777

h/em_reg.h

@@ -0,0 +1,10 @@
+/*
+ * mes ms_reg,offset,size,type,priority
+ *
+ * Here are the defines for type
+ */
+
+#define reg_any		0	/* Unspecified type */
+#define reg_loop	1	/* loop control variable */
+#define reg_pointer	2	/* pointer variable */
+#define reg_float	3	/* floating point variable */

h/pc_err.h

@@ -0,0 +1,22 @@
+#define	EARGC	64
+#define	EEXP	65
+#define	ELOG	66
+#define	ESQT	67
+#define	EASS	68
+#define	EPACK	69
+#define	EUNPACK	70
+#define	EMOD	71
+#define	EBADF	72
+#define	EFREE	73
+
+#define	EWRITEF	96
+#define	EREADF	97
+#define	EEOF	98
+#define	EFTRUNC	99
+#define	ERESET	100
+#define	EREWR	101
+#define	ECLOSE	102
+#define	EREAD	103
+#define	EWRITE	104
+#define	EDIGIT	105
+#define	EASCII	106

h/pc_file.h

@@ -0,0 +1,19 @@
+#define	WRBIT	0100000
+#define	TXTBIT	040000
+#define	EOFBIT	020000
+#define	ELNBIT	010000
+#define	WINDOW	04000
+#define	MAGIC	0252
+
+struct file {
+	char	*ptr;
+	unsigned flags;
+	char	*fname;
+	int	ufd;
+	int	size;
+	int	count;
+	int	buflen;
+	char	bufadr[512];
+};
+
+#define	EXTFL(z)	((struct file *)(_hbase + _extfl[z]))

h/pc_size.h

@@ -0,0 +1,21 @@
+/* fundamental */
+#define	sz_byte	1
+#define	sz_bool	1
+#define	sz_char	1
+
+/* fixed for the time being */
+#define	sz_word	2
+#define	sz_int	2
+#define	sz_long	4
+
+/* variable (see pc.c) */
+#define	sz_addr	sizes[0]
+#define	sz_real	sizes[1]
+#define	sz_head	sizes[2]
+#define	sz_buff	sizes[3]
+#define	sz_mset	sizes[4]
+#define	sz_iset	sizes[5]
+
+#define	sz_last	5
+
+#define	sz_proc	2*sz_addr

include/_tail_cc/setjmp.h

@@ -0,0 +1 @@
+typedef char jmp_buf[256];

include/_tail_mon/errno.h

@@ -0,0 +1,42 @@
+/*
+ * Error codes
+ */
+
+#define	EPERM	1
+#define	ENOENT	2
+#define	ESRCH	3
+#define	EINTR	4
+#define	EIO	5
+#define	ENXIO	6
+#define	E2BIG	7
+#define	ENOEXEC	8
+#define	EBADF	9
+#define	ECHILD	10
+#define	EAGAIN	11
+#define	ENOMEM	12
+#define	EACCES	13
+#define	EFAULT	14
+#define	ENOTBLK	15
+#define	EBUSY	16
+#define	EEXIST	17
+#define	EXDEV	18
+#define	ENODEV	19
+#define	ENOTDIR	20
+#define	EISDIR	21
+#define	EINVAL	22
+#define	ENFILE	23
+#define	EMFILE	24
+#define	ENOTTY	25
+#define	ETXTBSY	26
+#define	EFBIG	27
+#define	ENOSPC	28
+#define	ESPIPE	29
+#define	EROFS	30
+#define	EMLINK	31
+#define	EPIPE	32
+
+/* math software */
+#define	EDOM	33
+#define	ERANGE	34
+
+#define EQUOT	35

include/_tail_mon/signal.h

@@ -0,0 +1,21 @@
+#define NSIG 17
+
+#define	SIGHUP	1	/* hangup */
+#define	SIGINT	2	/* interrupt */
+#define	SIGQUIT	3	/* quit */
+#define	SIGILL	4	/* illegal instruction (not reset when caught) */
+#define	SIGTRAP	5	/* trace trap (not reset when caught) */
+#define	SIGIOT	6	/* IOT instruction */
+#define	SIGEMT	7	/* EMT instruction */
+#define	SIGFPE	8	/* floating point exception */
+#define	SIGKILL	9	/* kill (cannot be caught or ignored) */
+#define	SIGBUS	10	/* bus error */
+#define	SIGSEGV	11	/* segmentation violation */
+#define	SIGSYS	12	/* bad argument to system call */
+#define	SIGPIPE	13	/* write on a pipe with no one to read it */
+#define	SIGALRM	14	/* alarm clock */
+#define	SIGTERM	15	/* software termination signal from kill */
+
+int	(*signal())();
+#define	SIG_DFL	(int (*)())0
+#define	SIG_IGN	(int (*)())1

lang/basic/lib/LIST

@@ -0,0 +1,34 @@
+tail_bc.a
+abs.c
+asc.c
+asrt.c
+atn.c
+chr.c
+conversion.c
+hlt.c
+mki.c
+oct.c
+peek.c
+power.c
+exp.c
+log.c
+print.c
+io.c
+random.c
+read.c
+return.c
+sgn.c
+sin.c
+fif.e
+sqt.c
+fef.e
+stop.c
+string.c
+salloc.c
+swap.c
+trace.c
+write.c
+file.c
+error.c
+trap.c
+setline.e

lang/basic/lib/abs.c

@@ -0,0 +1,10 @@
+/* $Header$ */
+
+long _abl(i) long i;
+{
+	return( i>=0?i:-i);
+}
+double _abr(f) double f;
+{	
+	return( f>=0.0?f: -f);
+}

lang/basic/lib/asc.c

@@ -0,0 +1,11 @@
+#include "bc_string.h"
+
+/* $Header$ */
+
+int _asc(str)
+String *str;
+{
+	if(str==0 || str->strval==0)
+		error(3);
+	return( *str->strval);
+}

lang/basic/lib/asrt.c

@@ -0,0 +1,9 @@
+/* $Header$ */
+
+asrt(b)
+{
+	if(!b){
+		printf("ASSERTION ERROR\n");
+		abort();
+	}
+}

lang/basic/lib/atn.c

@@ -0,0 +1,93 @@
+/*
+ * (c) copyright 1983 by the Vrije Universiteit, Amsterdam, The Netherlands.
+ *
+ *          This product is part of the Amsterdam Compiler Kit.
+ *
+ * Permission to use, sell, duplicate or disclose this software must be
+ * obtained in writing. Requests for such permissions may be sent to
+ *
+ *      Dr. Andrew S. Tanenbaum
+ *      Wiskundig Seminarium
+ *      Vrije Universiteit
+ *      Postbox 7161
+ *      1007 MC Amsterdam
+ *      The Netherlands
+ *
+ */
+
+/* $Header$ */
+
+/* Author: J.W. Stevenson */
+
+/*
+	floating-point arctangent
+
+	atan returns the value of the arctangent of its
+	argument in the range [-pi/2,pi/2].
+
+	there are no error returns.
+
+	coefficients are #5077 from Hart & Cheney. (19.56D)
+*/
+
+
+static double sq2p1	= 2.414213562373095048802e0;
+static double sq2m1	=  .414213562373095048802e0;
+static double pio2	= 1.570796326794896619231e0;
+static double pio4	=  .785398163397448309615e0;
+static double p4	=  .161536412982230228262e2;
+static double p3	=  .26842548195503973794141e3;
+static double p2	=  .11530293515404850115428136e4;
+static double p1	=  .178040631643319697105464587e4;
+static double p0	=  .89678597403663861959987488e3;
+static double q4	=  .5895697050844462222791e2;
+static double q3	=  .536265374031215315104235e3;
+static double q2	=  .16667838148816337184521798e4;
+static double q1	=  .207933497444540981287275926e4;
+static double q0	=  .89678597403663861962481162e3;
+
+/*
+	xatan evaluates a series valid in the
+	range [-0.414...,+0.414...].
+*/
+
+static double
+xatan(arg)
+double arg;
+{
+	double argsq;
+	double value;
+
+	argsq = arg*arg;
+	value = ((((p4*argsq + p3)*argsq + p2)*argsq + p1)*argsq + p0);
+	value = value/(((((argsq + q4)*argsq + q3)*argsq + q2)*argsq + q1)*argsq + q0);
+	return(value*arg);
+}
+
+static double
+satan(arg)
+double arg;
+{
+	if(arg < sq2m1)
+		return(xatan(arg));
+	else if(arg > sq2p1)
+		return(pio2 - xatan(1/arg));
+	else
+		return(pio4 + xatan((arg-1)/(arg+1)));
+}
+
+
+/*
+	atan makes its argument positive and
+	calls the inner routine satan.
+*/
+
+double
+_atn(arg)
+double arg;
+{
+	if(arg>0)
+		return(satan(arg));
+	else
+		return(-satan(-arg));
+}

lang/basic/lib/chr.c

@@ -0,0 +1,17 @@
+#include "bc_string.h"
+
+/* $Header$ */
+
+String *_chr(i)
+int i;
+{
+	String	*s;
+	char	buf[2];
+
+	if( i<0 || i>127)
+		error(3);
+	buf[0]=i;
+	buf[1]=0;
+	s= _newstr(buf);
+	return(s);
+}

lang/basic/lib/conversion.c

@@ -0,0 +1,40 @@
+/* $Header$ */
+
+int _cint(f) double f;
+{
+	int r;
+	if( f<-32768 || f>32767) error(4);
+	if(f<0)
+		r= f-0.5;
+	else	r= f+0.5;
+	return(r);
+}
+
+double _trunc(f)
+double f;
+{
+	long d;
+	d=f;
+	f=d;
+	return( f );
+}
+
+double _fcint(f) double f;
+{
+	long r;
+	if(f<0){
+		r= -f;
+		r= -r -1;
+	}else	r= f;
+	f=r;
+	return(f);
+}
+int _fix(f)
+double f;
+{
+	int r;
+
+	if( f<-32768.0 || f>32767.0) error(4);
+	r= _sgn(f) * _fcint((f>0.0? f : -f));
+	return(r);
+}

lang/basic/lib/error.c

@@ -0,0 +1,63 @@
+/* $Header$ */
+
+/* error takes an error value in the range of 0-255 */
+/* and generates a trap */
+
+char *errortable[255]={
+/* 0  */	"",
+/* 1  */	"RETURN without GOSUB",
+/* 2  */	"Out of data",
+/* 3  */	"Illegal function call",
+/* 4  */	"Overflow",
+/* 5  */	"Out of memory",
+/*  6 */	"Undefined line ",
+/*  7 */	"Subscript out of range",
+/*  8 */	"Redimensioned array",
+/*  9 */	"Division by zero",
+/* 10 */	"Illegal indirect",
+/* 11 */	"Type mismatch",
+/* 12 */	"Out of string space",
+/* 13 */	"String too long",
+/* 14 */	"String formula too complex",
+/* 15 */	"Can't continue",
+/* 16 */	"Undefined user function",
+/* 17 */	"No resume",
+/* 18 */	"Resume without error",
+/* 19 */	"Unprintable error",
+/* 20 */	"Missing operand",
+/* 21 */	"Line buffer overflow",
+/* 22 */	"FOR without NEXT",
+/* 23 */	"WHILE without WEND",
+/* 24 */	"WEND without WHILE",
+/* 25 */	"Field overflow",
+/* 26 */	"Internal error",
+/* 27 */	"Bad file number",
+/* 28 */	"File not found",
+/* 29 */	"Bad file mode",
+/* 30 */	"File already open",
+/* 31 */	"Disk IO error",
+/* 32 */	"File already exists",
+/* 33 */	"Disk full",
+/* 34 */	"Input past end",
+/* 35 */	"Bad record number",
+/* 36 */	"Bad file name",
+/* 37 */	"Direct statement in file",
+/* 38 */	"Too many files",
+/* 39 */	"File not open",
+/* 40 */	"Syntax error in data",
+0
+};
+
+error(index)
+int	index;
+{
+	extern int _errsym;
+	extern int _erlsym;
+
+	_setline();
+	if( index<0 || index >40 )
+		printf("LINE %d:ERROR %d: Unprintable error\n",_erlsym,index);
+	else 	printf("LINE %d:ERROR %d: %s\n",_erlsym,index,errortable[index]);
+	_errsym= index;
+	_trap();
+}

lang/basic/lib/exp.c

@@ -0,0 +1,122 @@
+/*
+ * (c) copyright 1983 by the Vrije Universiteit, Amsterdam, The Netherlands.
+ *
+ *          This product is part of the Amsterdam Compiler Kit.
+ *
+ * Permission to use, sell, duplicate or disclose this software must be
+ * obtained in writing. Requests for such permissions may be sent to
+ *
+ *      Dr. Andrew S. Tanenbaum
+ *      Wiskundig Seminarium
+ *      Vrije Universiteit
+ *      Postbox 7161
+ *      1007 MC Amsterdam
+ *      The Netherlands
+ *
+ */
+
+/* $Header$ */
+
+/* Author: J.W. Stevenson */
+
+extern double	_fif();
+extern double	_fef();
+
+/*
+	exp returns the exponential function of its
+	floating-point argument.
+
+	The coefficients are #1069 from Hart and Cheney. (22.35D)
+*/
+
+#define	HUGE	1.701411733192644270e38
+
+static double p0	=  .2080384346694663001443843411e7;
+static double p1	=  .3028697169744036299076048876e5;
+static double p2	=  .6061485330061080841615584556e2;
+static double q0	=  .6002720360238832528230907598e7;
+static double q1	=  .3277251518082914423057964422e6;
+static double q2	=  .1749287689093076403844945335e4;
+static double log2e	= 1.4426950408889634073599247;
+static double sqrt2	= 1.4142135623730950488016887;
+static double maxf	= 10000.0;
+
+static double
+floor(d)
+double d;
+{
+	if (d<0) {
+		d = -d;
+		if (_fif(d, 1.0, &d) != 0)
+			d += 1;
+		d = -d;
+	} else
+		_fif(d, 1.0, &d);
+	return(d);
+}
+
+static double
+ldexp(fr,exp)
+double fr;
+int exp;
+{
+	int	neg,i;
+
+	neg = 1;
+	if (fr < 0) {
+		fr = -fr;
+		neg = -1;
+	}
+	fr = _fef(fr, &i);
+	/*
+	while (fr < 0.5) {
+		fr *= 2;
+		exp--;
+	}
+	*/
+	exp += i;
+	if (exp > 127) {
+		error(3);
+		return(neg * HUGE);
+	}
+	if (exp < -127)
+		return(0);
+	while (exp > 14) {
+		fr *= (1<<14);
+		exp -= 14;
+	}
+	while (exp < -14) {
+		fr /= (1<<14);
+		exp += 14;
+	}
+	if (exp > 0)
+		fr *= (1<<exp);
+	if (exp < 0)
+		fr /= (1<<(-exp));
+	return(neg * fr);
+}
+
+double
+_exp(arg)
+double arg;
+{
+	double fract;
+	double temp1, temp2, xsq;
+	int ent;
+
+	if(arg == 0)
+		return(1);
+	if(arg < -maxf)
+		return(0);
+	if(arg > maxf) {
+		error(3);
+		return(HUGE);
+	}
+	arg *= log2e;
+	ent = floor(arg);
+	fract = (arg-ent) - 0.5;
+	xsq = fract*fract;
+	temp1 = ((p2*xsq+p1)*xsq+p0)*fract;
+	temp2 = ((xsq+q2)*xsq+q1)*xsq + q0;
+	return(ldexp(sqrt2*(temp2+temp1)/(temp2-temp1), ent));
+}

lang/basic/lib/fef.e

@@ -0,0 +1,23 @@
+#
+ mes 2,EM_WSIZE,EM_PSIZE
+
+; $Header$
+
+#define FARG    0
+#define ERES    EM_DSIZE
+
+; _fef is called with two parameters:
+;       - address of exponent result (ERES)
+;       - floating point number to be split (FARG)
+; and returns an EM_DSIZE-byte floating point number
+
+ exp $_fef
+ pro $_fef,0
+ lal FARG
+ loi EM_DSIZE
+ fef EM_DSIZE
+ lal ERES
+ loi EM_PSIZE
+ sti EM_WSIZE
+ ret EM_DSIZE
+ end ?

lang/basic/lib/fif.e

@@ -0,0 +1,25 @@
+#
+ mes 2,EM_WSIZE,EM_PSIZE
+
+; $Header$
+
+#define ARG1    0
+#define ARG2    EM_DSIZE
+#define IRES    2*EM_DSIZE
+
+; _fif is called with three parameters:
+;       - address of integer part result (IRES)
+;       - float two (ARG2)
+;       - float one (ARG1)
+; and returns an EM_DSIZE-byte floating point number
+
+ exp $_fif
+ pro $_fif,0
+ lal 0
+ loi 2*EM_DSIZE
+ fif EM_DSIZE
+ lal IRES
+ loi EM_PSIZE
+ sti EM_DSIZE
+ ret EM_DSIZE
+ end ?

lang/basic/lib/file.c

@@ -0,0 +1,135 @@
+#include "bc_string.h"
+#include <stdio.h>
+#include "bc_io.h"
+
+/* $Header$ */
+
+Filedesc	_fdtable[16];
+/* BASIC file descriptor table */
+/* Channel assignment:
+   -1		terminal IO
+    0		data file
+    1-15	user files
+*/
+
+
+
+int	_chann		= -1;
+FILE	*_chanrd	= stdin;
+FILE	*_chanwr	= stdout;
+
+_setchan(index)
+int index;
+{
+#ifdef DEBUG
+	printf("setchannel %d\n",index);
+#endif
+	fflush(_chanwr);
+	if( index == -1)
+	{
+		_chann= -1;
+		_chanrd= stdin;
+		_chanwr= stdout;
+		return;
+	}
+	if( index<0 || index>15)
+		error(27);
+	_chann=index;
+	_chanrd= _chanwr= _fdtable[index].fd;
+}
+
+_asschn()
+{
+#ifdef DEBUG
+	printf("_asschn %d\n",_chann);
+#endif
+	if( _chann == -1) return;
+#ifdef DEBUG
+	printf(" file %d\n", _fdtable[_chann].fd);
+#endif
+	if( _chann<0 || _chann>15)
+		error(27);
+	if( _fdtable[_chann].fd== 0)
+		error(39);
+	if( feof( _fdtable[_chann].fd))
+		error(2);
+}
+
+_clochn(nr)
+int nr;
+{
+	if( nr<1 || nr >15 || _fdtable[nr].fd==0) error(3);
+	fclose(_fdtable[nr].fd);
+	_fdtable[nr].fd=0; _fdtable[nr].fname=0;
+}
+
+_opnchn(reclen,fname,mode)
+String *mode,*fname;
+int	reclen;
+{
+	/* channel has been set */
+	FILE *f;
+	int m;
+
+#ifdef DEBUG
+	printf("open %d %s %s \n",reclen,mode->strval,fname->strval);
+#endif
+	/* check for opened/closed file */
+	if(_fdtable[_chann].fd)
+		error(30);
+	switch(*mode->strval)
+	{
+		case 'O':
+		case 'o':
+			if( (f=fopen(fname->strval,"w")) == NULL)
+				error(28);
+			m= OMODE;
+			break;
+		case 'I':
+		case 'i':
+			if( (f=fopen(fname->strval,"r")) == NULL)
+				error(28);
+			m= IMODE;
+			break;
+		case 'r':
+		case 'R':
+			if( (f=fopen(fname->strval,"a")) == NULL)
+				error(28);
+			m= RMODE;
+			break;
+		default:
+			printf("file mode %s\n",mode->strval);
+			error(29);
+	}
+	_chanrd= _fdtable[_chann].fd= f;
+	_fdtable[_chann].fname= fname->strval;
+	_fdtable[_chann].reclength= reclen;
+	_fdtable[_chann].mode= m;
+#ifdef DEBUG
+	printf("file descr %d\n",f);
+#endif
+}
+
+_ioeof(channel)
+int channel;
+{
+	FILE *fd;
+	char c;
+	if( channel<0 || channel >15) error(3);
+	fd= _fdtable[channel].fd;
+	if( fd==0)
+		error(3);
+	c=fgetc(fd);
+	if( feof(_fdtable[channel].fd) ) return(-1);
+	ungetc(c,fd);
+	return(0);
+}
+
+_close()
+{
+	/* close all open files */
+	int i;
+	for(i=1;i<16;i++)
+	if( _fdtable[i].fd)
+		_clochn(i);
+}

lang/basic/lib/hlt.c

@@ -0,0 +1,7 @@
+/* $Header$ */
+
+_hlt(nr)
+int nr;
+{
+	exit(nr);
+}

lang/basic/lib/io.c

@@ -0,0 +1,97 @@
+#include "bc_io.h"
+#include <sgtty.h>
+
+/* $Header$ */
+
+struct sgttyb _ttydef;
+
+/* BASIC has some nasty io characteristics */
+
+#define MAXWIDTH 255
+
+int	_width = 75, _pos=0, _zonewidth=15;
+
+_out(str)
+char *str;
+{
+	int pos;
+
+	if( _chann== -1) pos= _pos;
+	else pos= _fdtable[_chann].pos;
+	while( *str) 
+	{
+		if( pos>= _width){ _outnl(); pos=0;}
+		fputc(*str++, _chanwr);
+		pos++;
+	}
+	if( _chann== -1) _pos=pos;
+	else _fdtable[_chann].pos= pos;
+}
+
+_outnl()
+{
+	fputc('\n',_chanwr);
+	if( _chann == -1)
+		_pos=0;
+	else
+		_fdtable[_chann].pos=0;
+}
+_zone()
+{
+	/* go to next zone */
+	int pos;
+	if( _chann == -1)
+		pos= _pos;
+	else pos= _fdtable[_chann].pos;
+	do{
+		fputc(' ',_chanwr);
+		pos++;
+		if( pos==_width)
+		{
+			_outnl();
+			pos=0;
+			break;
+		}
+	} while( pos % _zonewidth != 0);
+	if( _chann== -1) _pos=pos;
+	else _fdtable[_chann].pos= pos;
+}
+_in(buf)
+char *buf;
+{
+	register int holder ;
+	char *c;
+	int pos;
+	if( _chann == -1)
+	{
+		pos= _pos;
+		gtty(0,_ttydef);
+		_ttydef.sg_flags &= ~ECHO;
+		stty(0,_ttydef);
+	}else pos= _fdtable[_chann].pos;
+	c= buf;
+	while( (holder = fgetc(_chanrd)) != EOF && holder != '\n'){
+		*c= holder ;
+		if( _chann == -1) putchar(holder);
+		c++; pos++;
+	}
+	*c= 0;
+	if( _chann== -1) 
+	{
+		_pos=pos;
+		_ttydef.sg_flags |= ECHO;
+		stty(0,_ttydef);
+	} else _fdtable[_chann].pos= pos;
+}
+_tab(x)
+int x;
+{
+	if( x> _width) error(3);
+	if( x< _pos) _outnl();
+	_spc(x-_pos);
+}
+_spc(x)
+int x;
+{
+	while(x-->0) _out(" ");
+}