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updated for photo-typesetter

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dick
1986-02-04 17:37:41 +00:00
parent d72f604a96
commit 80fd35f736
19 changed files with 3724 additions and 2420 deletions
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41
doc/em/mapping.nr
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@@ -14,46 +14,46 @@ with 64K bytes of address space.
Here we use a member of the EM family with 2-byte word and pointer
size.
The most straightforward layout is shown in figure 2.
.N 1
.DS
65534 -> |-------------------------------|
.Dr 40
65534 \-> |-------------------------------|
|///////////////////////////////|
|//// unimplemented memory /////|
|///////////////////////////////|
ML -> |-------------------------------|
ML \-> |-------------------------------|
| |
| | <- LB
| | <\- LB
| stack and local area |
| |
|-------------------------------| <- SP
|-------------------------------| <\- SP
|///////////////////////////////|
|//////// inaccessible /////////|
|///////////////////////////////|
|-------------------------------| <- HP
|-------------------------------| <\- HP
| |
| heap area |
| |
| |
HB -> |-------------------------------|
HB \-> |-------------------------------|
| |
| global data area |
| |
EB -> |-------------------------------|
EB \-> |-------------------------------|
| |
| program text | <- PC
| program text | <\- PC
| |
| ( and tables ) |
| |
| |
PB -> |-------------------------------|
PB \-> |-------------------------------|
|///////////////////////////////|
|////////// undefined //////////|
|///////////////////////////////|
0 -> |-------------------------------|
0 \-> |-------------------------------|
.Df
Figure 2. Memory layout showing typical register
positions during execution of an EM program.
.DE 2
.De
.N 1
The base registers for the various memory pieces can be stored
in target machine registers or memory.
.IS
@@ -123,8 +123,7 @@ upside down, as shown in figure 3.
This is possible because the pointer format is explicitly undefined.
The first element of a word array will have a
lower physical address than the second element.
.N 2
.DS
.Dr 18
| | | |
| EB=60 | | ^ |
| | | | |
@@ -140,18 +139,18 @@ lower physical address than the second element.
| | | |
Type A Type B
.sp 2
.Df
Figure 3. Two possible memory implementations.
Numbers within the boxes are EM addresses.
The other numbers are physical addresses.
.DE 2
.De
.A 0 0
So, we have two different EM memory implementations:
.IS
.PS - 4
.PT A~-
.PT A~\-
stack downwards
.PT B~-
.PT B~\-
stack upwards
.PE
.IE
@@ -188,7 +187,7 @@ ADP:3:pop:r0:pop:r0
::push:r0:push:r0
LOI:1:pop:r0:pop:r0
::-::neg:r0
::\-::neg:r0
::clr:r1:clr:r1
::bisb:eb(r0),r1:bisb:eb(r0),r1
::push:r1:push:r1