部件x86-16中的模式X，为什么不打印平面1，而所有其他平面的顺序都不正确? [英] Mode X in Assembly x86-16, Why is plane 1 not printing and all the other planes are not in the correct order?
问题描述
我正在DosBox 0.74上用TASM 3.0编写，并且我试图用模式x (已调整13h，未链接模式13 )，但是您可以在图中看到，这不太正确. 看来平面1(第二平面)根本没有打印，而所有其他平面的顺序都不正确. 我知道这里的代码效率低下，但是我想使其正常工作然后清理.
proc showBMP
push cx
mov ax, 0A000h
mov es, ax
mov cx, [BMPHeight]
mov ax, [BMPWidth]
xor dx, dx
mov si, 4
div si
mov bp, dx
mov dx, [BMPX]
showBMP_nextLine:
call VGAPlaneStartBMP
push cx
push dx
mov di, cx
add di, [BMPY]
mov cx, di
shl cx, 6
shl di, 8
add di, cx
add di, dx
mov ah, 3fh
mov cx, [BMPWidth]
add cx, bp
mov dx, offset BMPMaxLine
int 21h
cld
mov cx, [BMPWidth]
mov si, offset BMPMaxLine
showBMP_nextLine_movsbLoop:
push cx
push di
shr di, 2
mov cl, [ds:si]
mov [es:di], cl
inc [VGAPlane]
inc si
pop di
inc di
pop cx
call VGAPlaneSelect
loop showBMP_nextLine_movsbLoop
pop dx
pop cx
loop showBMP_nextLine
pop cx
ret
endp showBMP
在这里您可以看到打印位图文件的过程，该过程在链4模式13上运行良好.
- BMPHeight-顾名思义，是图片的高度
- BMPWidth-相同
- BMPX-图片在屏幕上开始的位置(x坐标)
- BMPY-相同，但Y坐标
- BMPMaxLine-320数组用作缓冲区
- VGAPlane-0/1/2/3其中一个平面
proc VGAPlaneStartBMP
push ax
push bx
mov ax, [BMPX]
mov bx, offset PlaneByX
add bx, ax
mov al, [bx]
mov [VGAPlane], al
pop bx
pop ax
call VGAPlaneSelect
ret
endp VGAPlaneStartBMP
对于每行打印，此过程均以行的开头x选择平面:
-
PlaneByX-MAX_WIDTH/NUMBER_OF_PLANES个重复项(PLANES)，已重置
-
MAX_WIDTH为320，NUMBER_OF_PLANES为4，PLANES为0、1、2、3，
proc VGAPlaneSelect
push ax
push dx
mov al, 02h
mov dx, 03C4h
out dx, al
VGAPlaneSelect_start:
cmp [VGAPlane], 0
jne VGAPlaneSelect_0
mov al, 0h
jmp VGAPlaneSelect_end
VGAPlaneSelect_0:
cmp [VGAPlane], 1
jne VGAPlaneSelect_1
mov al, 1h
jmp VGAPlaneSelect_end
VGAPlaneSelect_1:
cmp [VGAPlane], 2
jne VGAPlaneSelect_2
mov al, 4h
jmp VGAPlaneSelect_end
VGAPlaneSelect_2:
cmp [VGAPlane], 3
jne VGAPlaneSelect_3
mov al, 8h
jmp VGAPlaneSelect_end
VGAPlaneSelect_3:
mov [VGAPlane], 0
jmp VGAPlaneSelect_start
VGAPlaneSelect_end:
inc dx
out dx, al
pop dx
pop ax
ret
endp VGAPlaneSelect
最后，这段代码是在选择飞机时使用的.
感谢Fuz找到答案，并感谢Jonathon Reinhart澄清了我的问题. 在VGAPlaneSelect过程中，al值(0x3c5 VGA地址的输出)应为2 ^(您要选择的平面)，对于平面0 2 ^ 0则应为1，我写了0
如此:
cmp [VGAPlane], 0
jne VGAPlaneSelect_0
mov al, 1h
jmp VGAPlaneSelect_end
VGAPlaneSelect_0:
执行VGAPlaneSelect过程的更好方法是:
proc VGAPlaneSelect
push ax
push dx
push cx
mov al, 02h
mov dx, 03C4h
out dx, al
VGAPlaneSelect_start:
mov ax, 1
mov cl, [VGAPlane]
shl ax, cl
cmp [VGAPlane], 4
jne VGAPlaneSelect_end
mov [VGAPlane], 0
jmp VGAPlaneSelect_start
VGAPlaneSelect_end:
mov dx, 03C5h
out dx, al
pop cx
pop dx
pop ax
ret
endp VGAPlaneSelect
I am writing in TASM 3.0 on DosBox 0.74 and I am trying to write in Mode x (Tweaked 13h, unchained mode 13), but here you can see in the image, it's not quite right. It seems that plane 1 (second plane) is not printing at all, and all the others are not in the right order. I know that the code here is inefficient, but I want to make it work and then clean it up.
proc showBMP
push cx
mov ax, 0A000h
mov es, ax
mov cx, [BMPHeight]
mov ax, [BMPWidth]
xor dx, dx
mov si, 4
div si
mov bp, dx
mov dx, [BMPX]
showBMP_nextLine:
call VGAPlaneStartBMP
push cx
push dx
mov di, cx
add di, [BMPY]
mov cx, di
shl cx, 6
shl di, 8
add di, cx
add di, dx
mov ah, 3fh
mov cx, [BMPWidth]
add cx, bp
mov dx, offset BMPMaxLine
int 21h
cld
mov cx, [BMPWidth]
mov si, offset BMPMaxLine
showBMP_nextLine_movsbLoop:
push cx
push di
shr di, 2
mov cl, [ds:si]
mov [es:di], cl
inc [VGAPlane]
inc si
pop di
inc di
pop cx
call VGAPlaneSelect
loop showBMP_nextLine_movsbLoop
pop dx
pop cx
loop showBMP_nextLine
pop cx
ret
endp showBMP
Here you can see a procedure for printing a bitmap file, which worked perfectly on chain-4 mode 13.
- BMPHeight - as name suggest is the height of the picture
- BMPWidth - same
- BMPX - where the picture starts on the screen (x coordinate)
- BMPY - same but Y coordinate
- BMPMaxLine - array of 320 works as a buffer
- VGAPlane - 0/1/2/3 one of the planes
proc VGAPlaneStartBMP
push ax
push bx
mov ax, [BMPX]
mov bx, offset PlaneByX
add bx, ax
mov al, [bx]
mov [VGAPlane], al
pop bx
pop ax
call VGAPlaneSelect
ret
endp VGAPlaneStartBMP
This procedure, for each line of printing, chooses the plane by the starting x of a line:
PlaneByX - MAX_WIDTH / NUMBER_OF_PLANES dup (PLANES), RESET
MAX_WIDTH is 320, NUMBER_OF_PLANES is 4, PLANES is 0, 1, 2, 3,
proc VGAPlaneSelect
push ax
push dx
mov al, 02h
mov dx, 03C4h
out dx, al
VGAPlaneSelect_start:
cmp [VGAPlane], 0
jne VGAPlaneSelect_0
mov al, 0h
jmp VGAPlaneSelect_end
VGAPlaneSelect_0:
cmp [VGAPlane], 1
jne VGAPlaneSelect_1
mov al, 1h
jmp VGAPlaneSelect_end
VGAPlaneSelect_1:
cmp [VGAPlane], 2
jne VGAPlaneSelect_2
mov al, 4h
jmp VGAPlaneSelect_end
VGAPlaneSelect_2:
cmp [VGAPlane], 3
jne VGAPlaneSelect_3
mov al, 8h
jmp VGAPlaneSelect_end
VGAPlaneSelect_3:
mov [VGAPlane], 0
jmp VGAPlaneSelect_start
VGAPlaneSelect_end:
inc dx
out dx, al
pop dx
pop ax
ret
endp VGAPlaneSelect
And lastly this code is when selecting a plane.
Thanks to Fuz for finding an answer and Jonathon Reinhart for making my question clearer. in the VGAPlaneSelect procedure, the al values, which are outputs for the 0x3c5 VGA address, should be 2^(the plane that you want to choose), and for plane 0 2^0 it should be 1, and I wrote 0
so:
cmp [VGAPlane], 0
jne VGAPlaneSelect_0
mov al, 1h
jmp VGAPlaneSelect_end
VGAPlaneSelect_0:
a better way to do the VGAPlaneSelect procedure is:
proc VGAPlaneSelect
push ax
push dx
push cx
mov al, 02h
mov dx, 03C4h
out dx, al
VGAPlaneSelect_start:
mov ax, 1
mov cl, [VGAPlane]
shl ax, cl
cmp [VGAPlane], 4
jne VGAPlaneSelect_end
mov [VGAPlane], 0
jmp VGAPlaneSelect_start
VGAPlaneSelect_end:
mov dx, 03C5h
out dx, al
pop cx
pop dx
pop ax
ret
endp VGAPlaneSelect
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