MSU1 AV player demo

snes/msu1/Makefile

@@ -1,4 +1,4 @@
-OBJS = header.ips reset.o65 main.o65 data.o65 const.o65 dma.o65 msu1.o65 # gfx.o65 # vars.o65
+OBJS = header.ips reset.o65 main.o65 data.o65 const.o65 dma.o65 msu1.o65 spc.o65 # gfx.o65 # vars.o65
 
 all: msu1vid.sfc
 

snes/msu1/const.a65

@@ -14,11 +14,9 @@ hdma_blank	.byt 40
 
 ; h/vscroll: write to $210d twice, write to $210e twice (mode 3)
 ; adjust hscroll and vscroll to split one tilemap row into two display rows
-; (tilemap memory saving measure)
-hdma_scroll	.byt 40
-		.word 0
-		.word 511
-		.byt 16
+; in conjunction with 16x16 tiles this reduces the effective tilemap size
+; to 288 bytes
+hdma_scroll	.byt 56
 		.word 0
 		.word 152+255
 		.byt 16
@@ -51,13 +49,13 @@ hdma_scroll	.byt 40
 ; tilemap address switch: write to $2107 once (mode 0)
 ; last row of tilemap is located elsewhere due to size
 hdma_tilemap	.byt 40
-		.byt $3c
+		.byt $bc
 		.byt 127
-		.byt $3c
+		.byt $bc
 		.byt 1
-		.byt $3c
+		.byt $bc
 		.byt 1
-		.byt $7c
+		.byt $fc
 		.byt 0
 
 ; tilemap part 1 (goes to VRAM 7F00-7FFF)
@@ -89,3 +87,29 @@ tilemap		.word $0000, $0000, $0002, $0004, $0006, $0008, $000a, $000c
 tilemap2	.word $0000, $01c0, $01c2, $01c4, $01c6, $01c8, $01ca, $01cc
 		.word $01ce, $01e0, $01e2, $01e4, $01e6, $01e8, $01ea, $0000
 
+spcaddr		.word $0100	; target address
+spcexec		.word $0100	; execute address
+spclen		.byt 100	; length
+
+spccode		.byt $e8, $6c		; - MOV A, #$6c
+		.byt $c4, $f2		; MOV $f2, A
+		.byt $e8, $20		; MOV A, #$20
+		.byt $c4, $f3		; MOV $f3, A
+		.byt $78, $20, $f3	; CMP $f3, #$20
+		.byt $d0, $f3		; BNE -
+
+		.byt $e8, $2c		; - MOV A, #$6c
+		.byt $c4, $f2		; MOV $f2, A
+		.byt $e8, $00		; MOV A, #$20
+		.byt $c4, $f3		; MOV $f3, A
+		.byt $78, $00, $f3	; CMP $f3, #$20
+		.byt $d0, $f3		; BNE -
+
+		.byt $e8, $3c		; - MOV A, #$6c
+		.byt $c4, $f2		; MOV $f2, A
+		.byt $e8, $00		; MOV A, #$20
+		.byt $c4, $f3		; MOV $f3, A
+		.byt $78, $00, $f3	; CMP $f3, #$20
+		.byt $d0, $f3		; BNE -
+
+		.byt $2f, $fe		; - BRA -

snes/msu1/dma.a65

@@ -49,10 +49,12 @@ setup_hdma:
 	sty $4332
 	sta $4334
 
-	ldx #184		;Set IRQ trigger to line 184
+	ldx #185		;Set IRQ trigger to line 185
 	stx $4209		;
-	lda #$a1		;NMI + V-Count IRQ + Auto Joypad Read
+	lda #$21		;V-Count IRQ + Auto Joypad Read
 	sta $4200
+	lda #$0e
+	sta $420c
 	rts
 
 

snes/msu1/header.a65

@@ -9,23 +9,22 @@ RESET:
         jmp @GAME_MAIN
 
 NMI_16bit:
-        php
-         rep #$30 : .al : .xl
-         pha: phx: phy: phd: phb
-          jsl @NMI_ROUTINE
-          rep #$30 : .al : .xl
-int_exit:
-         plb: pld: ply: plx: pla
-        plp
+	pha
+	sep #$20 : .as
+        lda $4210       ; ack interrupt
+        lda #$0e
+        sta $420c  ; enable HDMA ch. 1-3
+	pla
         rti
 
 IRQ_16bit:
-        php
-         rep #$30 : .al : .xl
-         pha: phx: phy: phd: phb
-          jsl @IRQ_ROUTINE
-          rep #$30 : .al : .xl
-          bra int_exit
+	pha
+	sep #$20 : .as
+        lda #$01
+        sta isr_flag
+        lda $4211  ;Acknowledge irq
+	pla
+        rti
 
 ;error vectors
 ABT_8bit: ABT_16bit:

snes/msu1/main.a65

@@ -6,6 +6,7 @@ GAME_MAIN:
 	jsr killdma
 	jsr waitblank
 	jsr snes_init
+	jsr spc_upload
 	lda #$01
 	sta $420d ; fast cpu
 	jsr setup_gfx
@@ -148,8 +149,7 @@ snes_init:
 	stz $420a		;
 	stz $420b		;
 	stz $420c		;
-	lda #$01
-	sta $420d		; FAAAAAST
+	stz $420d		; FAAAAAST
 	lda #$8f
 	sta $2100		;INIDISP: force blank
 	stz $2101		;

snes/msu1/msu1.a65

@@ -9,6 +9,10 @@ msu1init:
 	stx MSU_SEEK_BANK
 -	bit MSU_STATUS
 	bmi -
+
+	stx MSU_TRACK
+-	bit MSU_STATUS
+	bvs -
 	ldx #$0000
 	stx $2116
 
@@ -27,6 +31,8 @@ msu1loop:
 	sep #$20 : .as
 	rep #$10 : .xl
 	stz dispcnt
+	lda #$01
+	sta MSU_CONTROL
 msu1loop2
 	lda isr_flag
 	beq msu1loop2
@@ -45,7 +51,6 @@ msu1loop2
 	cmp #$02
 	bne msu1loop2
 
-	stz dispcnt
 	;load palette
 	stz $2121
 	lda #$22
@@ -56,6 +61,7 @@ msu1loop2
 	stx $4305
 	lda #$01
 	sta $420b
+	stz dispcnt
 	lda charptr
 	bne ptr2
 ptr1
@@ -64,10 +70,10 @@ ptr1
 	sta charptr
 	ldx #$0000
 	stx $2116
-	bra msu1loop2
+	jmp msu1loop2
 ptr2
 	stz $210b
 	stz charptr
 	ldx #$4000
 	stx $2116
-	bra msu1loop2
+	jmp msu1loop2

snes/msu1/reset.a65

@@ -11,16 +11,20 @@
 ; NMI - called on VBlank
 NMI_ROUTINE:
         sep #$20 : .as
+	pha
         lda $4210	; ack interrupt
-	lda #$0e
-	sta $420c  ; enable HDMA ch. 1-3
+;	lda #$0e
+;	sta $420c  ; enable HDMA ch. 1-3
+	pla
         rtl
 
 ; IRQ - called when triggered
 IRQ_ROUTINE:
         sep #$20 : .as
+	pha
+        lda $4211  ;Acknowledge irq
 	lda #$01
 	sta isr_flag
-        lda $4211  ;Acknowledge irq
+	pla
         rtl
 

snes/msu1/spc.a65

@@ -0,0 +1,50 @@
+spc_upload:
+	rep #$20 : .al
+	sep #$10 : .xs
+
+	lda #$bbaa	; wait for IPL bootup
+-	cmp $2140
+	bne -
+
+	; IPL protocol: $2142-3 = target address
+	lda @spcaddr
+	sta $2142
+	ldx #$01
+	stx $2141
+	ldx #$cc
+	stx $2140
+	; wait for echo
+-	cpx $2140
+	bne -
+
+	; init counters
+	sep #$20 : .as
+	ldx #$00	; sequence counter
+	lda @spclen
+	tay		; countdown
+spc_loop
+	lda @spccode, x	; fill data byte
+	sta $2141	; write data...
+	stx $2140	; ...and write sequence counter
+-	cpx $2140	; wait for echo from IPL
+	bne -
+	inx		; increment sequence counter...
+	dey
+	bne spc_loop	; if not, do it again
+
+spc_end
+	rep #$20 : .al
+	lda @spcexec
+	sta $2142
+	stz $2141	; data = 0
+	ldx $2140
+	inx
+	inx
+	stx $2140	; send sequence end / execute
+-	cpx $2140	; wait for last echo
+	bne -
+
+	sep #$20 : .as
+	rep #$10 : .xl
+
+	rts		; and done!