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?

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 VGAPlaneSelectI 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 retendp showBMPHere 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 pictureBMPWidth - same BMPX - where the picture starts on the screen (x coordinate)BMPY - same but Y coordinate BMPMaxLine - array of 320 works as a bufferVGAPlane - 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 VGAPlaneStartBMPThis procedure, for each line of printing, chooses the plane by the starting x of a line:PlaneByX - MAX_WIDTH / NUMBER_OF_PLANES dup (PLANES), RESETMAX_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 VGAPlaneSelectAnd lastly this code is when selecting a plane. 解决方案 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 0so: 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 这篇关于部件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?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！