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VRam read fix (fixes Equinox)

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zsknight
2001-05-18 01:02:21 +00:00
parent 8053ed202e
commit bf196afea8
1 changed files with 9 additions and 14 deletions
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23
zsnes/src/cpu/regs.inc
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@@ -293,7 +293,7 @@ NEWSYM bg3scroly, dw 0 ; background 3 y position
NEWSYM bg4scroly, dw 0 ; background 4 y position NEWSYM bg4scroly, dw 0 ; background 4 y position
NEWSYM addrincr, dw 2 ; vram increment (2,64,128,256) NEWSYM addrincr, dw 2 ; vram increment (2,64,128,256)
NEWSYM vramincr, db 0 ; 0 = inrement at 2118/2139, 1 = 2119,213A NEWSYM vramincr, db 0 ; 0 = inrement at 2118/2139, 1 = 2119,213A
NEWSYM vramread, db 0 ; 0 = address set, 1 = already read once NEWSYM vramread, db 0 ; previous character for vram read
NEWSYM vramaddr, dd 0 ; vram address NEWSYM vramaddr, dd 0 ; vram address
NEWSYM cgaddr, dw 0 ; cg (palette) address NEWSYM cgaddr, dw 0 ; cg (palette) address
NEWSYM cgmod, db 0 ; if cgram is modified or not NEWSYM cgmod, db 0 ; if cgram is modified or not
@@ -389,8 +389,9 @@ NEWSYM SDD1BankA, db 0
NEWSYM SDD1BankB, db 1 NEWSYM SDD1BankB, db 1
NEWSYM SDD1BankC, db 2 NEWSYM SDD1BankC, db 2
NEWSYM SDD1BankD, db 3 NEWSYM SDD1BankD, db 3
NEWSYM vramread2, db 0 ; previous character for vram read
NEWSYM tempdat, times 484 db 0 ; expandable area NEWSYM tempdat, times 483 db 0 ; expandable area
num2writeppureg equ $-sndrot num2writeppureg equ $-sndrot
; pharos equ hack *sigh* ; pharos equ hack *sigh*
@@ -573,11 +574,11 @@ reg2139r:
xor ebx,ebx xor ebx,ebx
mov bx,[vramaddr] mov bx,[vramaddr]
add ebx,[vram] add ebx,[vram]
mov al,[ebx] mov bl,[ebx]
mov al,[vramread]
mov [vramread],bl
cmp byte[vramincr],0 cmp byte[vramincr],0
je .noincr je .noincr
cmp byte[vramread],0
je .noincr2
mov bx,[addrincr] mov bx,[addrincr]
add [vramaddr],bx add [vramaddr],bx
cmp byte[vramincby8on],1 cmp byte[vramincby8on],1
@@ -597,20 +598,17 @@ reg2139r:
sub word[vramaddr],16 sub word[vramaddr],16
.noincr .noincr
ret ret
.noincr2
mov byte[vramread],1
ret
; Read VRAM Data (High) ; Read VRAM Data (High)
reg213Ar: reg213Ar:
xor ebx,ebx xor ebx,ebx
mov bx,[vramaddr] mov bx,[vramaddr]
add ebx,[vram] add ebx,[vram]
mov al,[ebx+1] mov bl,[ebx+1]
mov al,[vramread2]
mov [vramread2],bl
cmp byte[vramincr],1 cmp byte[vramincr],1
je .noincr je .noincr
cmp byte[vramread],0
je .noincr2
mov bx,[addrincr] mov bx,[addrincr]
add [vramaddr],bx add [vramaddr],bx
cmp byte[vramincby8on],1 cmp byte[vramincby8on],1
@@ -630,9 +628,6 @@ reg213Ar:
sub word[vramaddr],16 sub word[vramaddr],16
.noincr .noincr
ret ret
.noincr2
mov byte[vramread],1
ret
; Read CGRAM Data ; Read CGRAM Data
reg213Br: reg213Br: