dma.asm

十七种模拟器源代码 非常有用的作课程设计不可缺少的

    shl ebx,2
    add ebx,[regptw]
    mov eax,[ebx]
    mov [edx+8],eax

    ; get pointer #4
    xor ebx,ebx
    mov bl,[esi+1]      ; PPU memory - 21xx
    mov bh,21h
    add bx,[edi+6]
    cmp bx,2118h
    je .notnormalhdma4
    cmp bx,2119h
    je .notnormalhdma4
    jmp .normalhdma4
.notnormalhdma4
    mov bx,2200h        ; bad hack _Demo_
.normalhdma4
    shl ebx,2
    add ebx,[regptw]
    mov eax,[ebx]
    mov [edx+12],eax

    xor ebx,ebx
    pop eax
    and [hdmatype],ah
    ret
.nohdma
    pop eax
    and [nexthdma],ah
    ret

.addrwrite dw 0,0,0,0, 0,1,0,1, 0,0,0,0, 0,0,1,1, 0,1,2,3, 0,1,2,3, 0,1,2,3
           dw 0,1,2,3
.addrnumt  db 1,2,2,4,4,4,4,4

NEWSYM hdmastartsc, db 0
NEWSYM hdmarestart, db 0

NEWSYM reg420Cw

    mov [curhdma],al
    mov bx,[resolutn]
    cmp word[curypos],bx
    jae near .nohdma
    cmp byte[disablehdma],0
    jne near .nohdma
;    jmp starthdma
    mov al,[curhdma]
    mov [nexthdma],al
    cmp al,0
    je near .nohdma
    push ebx
    push esi
    push edi
    push ecx
    push edx
    mov esi,dmadata
    mov edx,hdmadata
    mov ah,01h
    test al,01h
    jz .notransa
    call setuphdma
.notransa
    add esi,16
    add edx,19
    mov ah,02h
    test al,02h
    jz .notransb
    call setuphdma
.notransb
    add esi,16
    add edx,19
    mov ah,04h
    test al,04h
    jz .notransc
    call setuphdma
.notransc
    add esi,16
    add edx,19
    mov ah,08h
    test al,08h
    jz .notransd
    call setuphdma
.notransd
    add esi,16
    add edx,19
    mov ah,10h
    test al,10h
    jz .notranse
    call setuphdma
.notranse
    add esi,16
    add edx,19
    mov ah,20h
    test al,20h
    jz .notransf
    call setuphdma
.notransf
    add esi,16
    add edx,19
    mov ah,40h
    test al,40h
    jz .notransg
    call setuphdma
.notransg
    add esi,16
    add edx,19
    mov ah,80h
    test al,80h
    jz .notransh
    call setuphdma
.notransh
    mov bl,[hdmaearlstart]
    mov [hdmadelay],bl
    pop edx
    pop ecx
    pop edi
    pop esi
    pop ebx
;    call exechdma
;    call exechdma
.nohdma
    mov byte[hdmarestart],0
    ret

; HDMA enable register
NEWSYM starthdma
    mov al,[curhdma]
NEWSYM startnexthdma
    mov [nexthdma],al
    cmp al,0
    je near .nohdma
    push ebx
    push esi
    push edi
    push ecx
    push edx
    mov esi,dmadata
    mov edx,hdmadata
    mov ah,01h
    test al,01h
    jz .notransa
    call setuphdma
.notransa
    add esi,16
    add edx,19
    mov ah,02h
    test al,02h
    jz .notransb
    call setuphdma
.notransb
    add esi,16
    add edx,19
    mov ah,04h
    test al,04h
    jz .notransc
    call setuphdma
.notransc
    add esi,16
    add edx,19
    mov ah,08h
    test al,08h
    jz .notransd
    call setuphdma
.notransd
    add esi,16
    add edx,19
    mov ah,10h
    test al,10h
    jz .notranse
    call setuphdma
.notranse
    add esi,16
    add edx,19
    mov ah,20h
    test al,20h
    jz .notransf
    call setuphdma
.notransf
    add esi,16
    add edx,19
    mov ah,40h
    test al,40h
    jz .notransg
    call setuphdma
.notransg
    add esi,16
    add edx,19
    mov ah,80h
    test al,80h
    jz .notransh
    call setuphdma
.notransh
    pop edx
    pop ecx
    pop edi
    pop esi
    pop ebx
.nohdma
    ret

NEWSYM dohdma
    xor ebx,ebx
    test byte[esi],40h
    jnz near indirectaddr
    push eax
    test byte[esi+10],07Fh
    jnz near .nozero
    test byte[esi+10],80h
    jnz near .noincr
    test [hdmatype],ah
    jnz .noincr
    mov bl,[edx+16]
    add word[edx+17],bx
.noincr
    mov bl,ah
    not bl
    and [hdmatype],bl
    mov bl,[esi+4]
    mov cx,[edx+17]
    call dword near [memtabler8+ebx*4]
    inc word[edx+17]
    mov byte[esi+10],al
    test al,0FFh
    jnz .yeszero
    xor [nexthdma],ah
    jmp .finhdma2
.yeszero
    cmp byte[esi+10],80h
    ja near hdmatype2
    mov al,[edx+16]
    mov [.tempdecr],al
    xor ebx,ebx
    xor ecx,ecx
    mov bl,[esi+4]
    mov cx,[edx+17]         ; increment/decrement/keep pointer location
    call dword near [memtabler8+ebx*4]
    call dword near [edx]
    dec byte[.tempdecr]
    jz .finhdma
    xor ebx,ebx
    mov bl,[esi+4]
    mov cx,[edx+17]         ; increment/decrement/keep pointer location
    inc cx
    call dword near [memtabler8+ebx*4]
    call dword near [edx+4]
    dec byte[.tempdecr]
    jz .finhdma
    xor ebx,ebx
    mov bl,[esi+4]
    mov cx,[edx+17]         ; increment/decrement/keep pointer location
    add cx,2
    call dword near [memtabler8+ebx*4]
    call dword near [edx+8]
    dec byte[.tempdecr]
    jz .finhdma
    xor ebx,ebx
    mov bl,[esi+4]
    mov cx,[edx+17]         ; increment/decrement/keep pointer location
    add cx,3
    call dword near [memtabler8+ebx*4]
    call dword near [edx+12]
    jmp .finhdma
.nozero
    test byte[esi+10],80h
    jnz near hdmatype2
.finhdma
    mov ax,[edx+17]
    mov [esi+8],ax
    pop eax
    dec byte[esi+10]
    ret
.finhdma2
    mov ax,[edx+17]
    mov [esi+8],ax
    pop eax
    ret

.tempdecr db 0

NEWSYM hdmatype2
    mov al,[edx+16]
    mov [.tempdecr],al
    xor ebx,ebx
    xor ecx,ecx
    mov bl,[esi+4]
    mov cx,[edx+17]         ; increment/decrement/keep pointer location
    inc word[edx+17]
    call dword near [memtabler8+ebx*4]
    call dword near [edx]
    dec byte[.tempdecr]
    jz .finhdma
    xor ebx,ebx
    mov bl,[esi+4]
    mov cx,[edx+17]         ; increment/decrement/keep pointer location
    inc word[edx+17]
    call dword near [memtabler8+ebx*4]
    call dword near [edx+4]
    dec byte[.tempdecr]
    jz .finhdma
    xor ebx,ebx
    mov bl,[esi+4]
    mov cx,[edx+17]         ; increment/decrement/keep pointer location
    inc word[edx+17]
    call dword near [memtabler8+ebx*4]
    call dword near [edx+8]
    dec byte[.tempdecr]
    jz .finhdma
    xor ebx,ebx
    mov bl,[esi+4]
    mov cx,[edx+17]         ; increment/decrement/keep pointer location
    inc word[edx+17]
    call dword near [memtabler8+ebx*4]
    call dword near [edx+12]
.finhdma
    mov ax,[edx+17]
    mov [esi+8],ax
    pop eax
    dec byte[esi+10]
    ret

.tempdecr db 0

NEWSYM indirectaddr
    push eax
    test byte[esi+10],07Fh
    jnz near .nozero
    test [hdmatype],ah
    jnz .noincr
    add word[edx+17],2
.noincr
    mov bl,ah
    not bl
    and [hdmatype],bl
    mov bl,[esi+4]
    mov cx,[edx+17]
    call dword near [memtabler8+ebx*4]
    inc word[edx+17]
    mov byte[esi+10],al
    push eax
    mov bl,[esi+4]
    mov cx,[edx+17]
    call dword near [memtabler16+ebx*4]
    mov [esi+5],ax
    pop eax
    test al,0FFh
    jnz .yeszero
    xor [nexthdma],ah
    jmp .finhdma2
.yeszero
    cmp byte[esi+10],80h
    ja near hdmatype2indirect
    mov al,[edx+16]
    mov [.tempdecr],al
    xor ebx,ebx
    xor ecx,ecx
    mov bl,[esi+7]
    mov cx,[esi+5]         ; increment/decrement/keep pointer location
    call dword near [memtabler8+ebx*4]
    call dword near [edx]
    dec byte[.tempdecr]
    jz .finhdma
    xor ebx,ebx
    mov bl,[esi+7]
    mov cx,[esi+5]         ; increment/decrement/keep pointer location
    inc cx
    call dword near [memtabler8+ebx*4]
    call dword near [edx+4]
    dec byte[.tempdecr]
    jz .finhdma
    xor ebx,ebx
    mov bl,[esi+7]
    mov cx,[esi+5]         ; increment/decrement/keep pointer location
    add cx,2
    call dword near [memtabler8+ebx*4]
    call dword near [edx+8]
    dec byte[.tempdecr]
    jz .finhdma
    xor ebx,ebx
    mov bl,[esi+7]
    mov cx,[esi+5]         ; increment/decrement/keep pointer location
    add cx,3
    call dword near [memtabler8+ebx*4]
    call dword near [edx+12]
    jmp .finhdma
.nozero
    test byte[esi+10],80h
    jnz near hdmatype2indirect
.finhdma
    mov ax,[edx+17]
    mov [esi+8],ax
    pop eax
    dec byte[esi+10]
    ret
.finhdma2
    mov ax,[edx+17]
    mov [esi+8],ax
    pop eax
    ret

.tempdecr db 0
.fname2 db 9,'vram2.dat',0

NEWSYM hdmatype2indirect
    mov al,[edx+16]
    mov [.tempdecr],al
    xor ebx,ebx
    xor ecx,ecx
    mov bl,[esi+7]
    mov cx,[esi+5]         ; increment/decrement/keep pointer location
    inc word[esi+5]
    call dword near [memtabler8+ebx*4]
    call dword near [edx]
    dec byte[.tempdecr]
    jz .finhdma
    xor ebx,ebx
    mov bl,[esi+7]
    mov cx,[esi+5]         ; increment/decrement/keep pointer location
    inc word[esi+5]
    call dword near [memtabler8+ebx*4]
    call dword near [edx+4]
    dec byte[.tempdecr]
    jz .finhdma
    xor ebx,ebx
    mov bl,[esi+7]
    mov cx,[esi+5]         ; increment/decrement/keep pointer location
    inc word[esi+5]
    call dword near [memtabler8+ebx*4]
    call dword near [edx+8]
    dec byte[.tempdecr]
    jz .finhdma
    xor ebx,ebx
    mov bl,[esi+7]
    mov cx,[esi+5]         ; increment/decrement/keep pointer location
    inc word[esi+5]
    call dword near [memtabler8+ebx*4]
    call dword near [edx+12]
.finhdma
    pop eax
    dec byte[esi+10]
    ret

.tempdecr db 0


NEWSYM dohdma2
    ; new hdma routines
    xor ebx,ebx
    push eax
    test [hdmatype],ah
    jz .nostart
    xor ah,0FFh
    xor ecx,ecx
    and [hdmatype],ah
    test byte[esi],40h
    jnz near .indir
    mov bl,[esi+4]
    mov cx,[esi+8]
    call dword near [memtabler8+ebx*4]
    inc word[esi+8]
    xor ebx,ebx
    mov [esi+10],al
    jmp .nostart
.indir
    mov bl,[esi+4]
    mov [esi+7],bl
    mov cx,[esi+2]
    mov [esi+5],cx
    call dword near [memtabler8+ebx*4]
    xor ebx,ebx
    inc word[esi+5]
    mov bl,[esi+7]
    mov [esi+10],al
    mov cx,[esi+5]
    call dword near [memtabler8+ebx*4]
    xor ebx,ebx
    inc word[esi+5]
    mov bl,[esi+7]
    mov [esi+8],al
    mov cx,[esi+5]
    call dword near [memtabler8+ebx*4]
    inc word[esi+5]
    mov [esi+9],al
    xor ebx,ebx
.nostart

    cmp byte[esi+10],0
    je near .endhdma
    mov bl,[esi+4]
    mov al,[edx+16]
    mov [.tempdecr],al
    xor ecx,ecx
    mov bl,[esi+4]
    mov cx,[esi+8]         ; increment/decrement/keep pointer location
    call dword near [memtabler8+ebx*4]
    call dword near [edx]
    dec byte[.tempdecr]
    jz .nomorehdma
    xor ebx,ebx
    mov cx,[esi+8]         ; increment/decrement/keep pointer location
    mov bl,[esi+4]
    inc cx
    call dword near [memtabler8+ebx*4]
    call dword near [edx+4]
    dec byte[.tempdecr]
    jz .nomorehdma
    xor ebx,ebx
    mov cx,[esi+8]         ; increment/decrement/keep pointer location
    mov bl,[esi+4]
    add cx,2
    call dword near [memtabler8+ebx*4]
    call dword near [edx+8]
    dec byte[.tempdecr]
    jz .nomorehdma
    xor ebx,ebx
    mov cx,[esi+8]         ; increment/decrement/keep pointer location
    mov bl,[esi+4]
    add cx,3
    call dword near [memtabler8+ebx*4]
    call dword near [edx+12]
.nomorehdma
    dec byte[esi+10]
    test byte[esi+10],7Fh
    jz .zeroed
    test byte[esi+10],80h
    jz .noadd
    xor ebx,ebx
    mov bl,[edx+16]
    add [esi+8],bx
.noadd
    pop eax
    ret
.zeroed
    test byte[esi],40h
    jnz near .indirzero
    xor ebx,ebx
    mov bl,[edx+16]
    add [esi+8],bx
    mov bl,[esi+4]
    mov cx,[esi+8]
    call dword near [memtabler8+ebx*4]
    inc word[esi+8]
    mov [esi+10],al
    pop eax
    ret
.indirzero
    xor ebx,ebx
    mov bl,[esi+7]
    mov cx,[esi+5]
    call dword near [memtabler8+ebx*4]
    xor ebx,ebx
    inc word[esi+5]
    mov bl,[esi+7]
    mov [esi+10],al
    mov cx,[esi+5]
    call dword near [memtabler8+ebx*4]
    xor ebx,ebx
    inc word[esi+5]
    mov bl,[esi+7]
    mov [esi+8],al
    mov cx,[esi+5]
    call dword near [memtabler8+ebx*4]
    inc word[esi+5]
    mov [esi+9],al
    pop eax
    ret
.endhdma
    pop eax
    xor [nexthdma],ah
    ret

.tempdecr db 0

NEWSYM exechdma
    cmp byte[hdmarestart],1
    je near exechdmars
    mov al,[nexthdma]
    cmp al,0
    je near .nohdma
    push ebx
    push esi
    push edi
    push ecx
    push edx
    mov esi,dmadata
    mov edx,hdmadata
    mov ah,01h
    test al,01h
    jz .notransa
    call dohdma
.notransa
    add esi,16
    add edx,19
    mov ah,02h
    test al,02h
    jz .notransb
    call dohdma
.notransb
    add esi,16
    add edx,19
    mov ah,04h
    test al,04h
    jz .notransc
    call dohdma
.notransc
    add esi,16
    add edx,19
    mov ah,08h
    test al,08h
    jz .notransd
    call dohdma
.notransd
    add esi,16
    add edx,19
    mov ah,10h
    test al,10h
    jz .notranse
    call dohdma
.notranse
    add esi,16
    add edx,19
    mov ah,20h
    test al,20h
    jz .notransf
    call dohdma
.notransf
    add esi,16
    add edx,19
    mov ah,40h
    test al,40h
    jz .notransg
    call dohdma
.notransg
    add esi,16
    add edx,19
    mov ah,80h
    test al,80h
    jz .notransh
    call dohdma
.notransh
    pop edx
    pop ecx
    pop edi
    pop esi
    pop ebx
.nohdma
    ret

NEWSYM exechdmars
    mov al,[nexthdma]
    cmp al,0
    je near .nohdma
    push ebx
    push esi
    push edi
    push ecx
    push edx
    mov esi,dmadata
    mov edx,hdmadata
    mov ah,01h
    test al,01h
    jz .notransa
    call setuphdmars
    call dohdma
.notransa
    add esi,16
    add edx,19
    mov ah,02h
    test al,02h
    jz .notransb
    call setuphdmars
    call dohdma
.notransb
    add esi,16
    add edx,19
    mov ah,04h
    test al,04h
    jz .notransc
    call setuphdmars
    call dohdma
.notransc
    add esi,16
    add edx,19
    mov ah,08h
    test al,08h
    jz .notransd
    call setuphdmars
    call dohdma
.notransd
    add esi,16
    add edx,19
    mov ah,10h
    test al,10h
    jz .notranse
    call setuphdmars
    call dohdma
.notranse
    add esi,16
    add edx,19
    mov ah,20h
    test al,20h
    jz .notransf
    call setuphdmars
    call dohdma
.notransf
    add esi,16
    add edx,19
    mov ah,40h
    test al,40h
    jz .notransg
    call setuphdmars
    call dohdma
.notransg
    add esi,16
    add edx,19
    mov ah,80h
    test al,80h
    jz .notransh
    call setuphdmars
    call dohdma
.notransh
    pop edx
    pop ecx
    pop edi
    pop esi
    pop ebx
.nohdma
    mov byte[hdmarestart],0
    ret



NEWSYM DmaAsmEnd