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Proper latching of bit 7 on $4201

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pagefault
2003-05-06 01:40:05 +00:00
parent 3c2ec93237
commit f9a3133f4d
2 changed files with 20 additions and 1 deletions
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9
zsnes/src/cpu/regs.inc
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@@ -665,9 +665,10 @@ NEWSYM vramread2, db 0 ; previous character for vram read
NEWSYM nosprincr, db 0 NEWSYM nosprincr, db 0
NEWSYM poamaddrs, dw 0 NEWSYM poamaddrs, dw 0
NEWSYM ioportval, db 0 NEWSYM ioportval, db 0
NEWSYM iohvlatch, db 0
NEWSYM tempdat, times 479 db 0 ; expandable area NEWSYM tempdat, times 478 db 0 ; expandable area
num2writeppureg equ $-sndrot num2writeppureg equ $-sndrot
; pharos equ hack *sigh* ; pharos equ hack *sigh*
@@ -767,8 +768,11 @@ reg2137r:
; mov byte[debstop3],1 ; mov byte[debstop3],1
cmp byte[debuggeron],1 cmp byte[debuggeron],1
je .debugger je .debugger
cmp byte[iohvlatch],1
je .dolatch
test byte[ioportval],80h test byte[ioportval],80h
jnz .nolatch jnz .nolatch
.dolatch
xor ebx,ebx xor ebx,ebx
mov bl,[cycpl] mov bl,[cycpl]
sub bl,dh sub bl,dh
@@ -794,8 +798,11 @@ reg2137r:
ret ret
.debugger .debugger
debblah: debblah:
cmp byte[iohvlatch],1
je .dolatch2
test byte[ioportval],80h test byte[ioportval],80h
jnz .nolatch2 jnz .nolatch2
.dolatch2
xor ebx,ebx xor ebx,ebx
mov bl,[cycpl] mov bl,[cycpl]
sub bl,[pdh] sub bl,[pdh]

12
zsnes/src/cpu/regsw.inc
View File

@@ -1504,6 +1504,18 @@ reg4200w:
; Programmable I/O port (out-port) ; Programmable I/O port (out-port)
reg4201w: reg4201w:
cmp byte[iohvlatch],1
jne .noiohvlatch
test al,80h
jnz .noiohvlatch
mov byte[iohvlatch],0
.noiohvlatch
test byte[ioportval],80h
jnz .nolatch
test al,80h
jz .nolatch
mov byte[iohvlatch],1
.nolatch
mov byte[ioportval],al mov byte[ioportval],al
mov bl,al mov bl,al
and bl,80h and bl,80h