本文介绍了内存映射图形输出的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在探索使用内存映射图形绘制像素和线条.我在Windows的Textpad中使用TASM.当我单击运行时，整个屏幕变成蓝色，仅此而已，没有绘制像素.
I'm exploring into drawing pixels and lines, using Memory-Mapped Graphics. I'm using TASM in Textpad, in Windows. When I click run the whole screen turns blue and that's it, no pixels drawn.
.model small
.stack
.data
saveMode db ?
xVal dw ?
yVal dw ?
.code
main proc
mov ax, @data
mov ds, ax
call SetVideoMode
call SetScreenBackground
call Draw_Some_Pixels
call RestoreVideoMode
mov ax, 4c00h
int 21h
main endp
SetScreenBackground proc
mov dx, 3c8h
mov al, 0
out dx, al
mov dx, 3c9h
mov al, 0
out dx, al
mov al, 0
out dx, al
mov al, 35
out dx, al
ret
SetScreenBackground endp
SetVideoMode proc
mov ah, 0fh
int 10h
mov saveMode, al
mov ah, 0
mov al, 13h
int 10h
push 0A00h
pop es
ret
SetVideoMode endp
RestoreVideoMode proc
mov ah, 10h
int 16h
mov ah, 0
mov al, saveMode
int 10h
ret
RestoreVideoMode endp
Draw_Some_Pixels proc
mov dx, 3c8h
mov al, 1
out dx, al
mov dx, 3c9h
mov al, 63
out dx, al
mov al, 63
out dx, al
mov al, 63
out dx, al
mov xVal, 160
mov yVal, 100
mov ax, 320
mul yVal
add ax, xVal
mov cx, 10
mov di, ax
DP1:
mov BYTE PTR es:[di], 1
add di, 5
Loop DP1
ret
Draw_Some_Pixels endp
推荐答案
问题似乎出在视频模式13h 与之关联.
The issue seems to be with the segment that video mode 13h is associated with.
您的代码可以:
SetVideoMode proc
mov ah, 0fh
int 10h
mov saveMode, al
mov ah, 0
mov al, 13h ; Video mode 13h
int 10h
push 0A00h ; Incorrect should be 0A000h
pop es
ret
SetVideoMode endp
视频模式13h将以0A000h:0的segment:offset(在您的情况下为 ES:0 )寻址. 0A000h:0是物理地址(0A000h<< 4)+ 0 = 0A0000h.
Video mode 13h would be addressed with a segment:offset (ES:0 in your case) of 0A000h:0. 0A000h:0 would be physical address (0A000h << 4) + 0 = 0A0000h.
可以通过将代码更改为以下代码来修复该代码:
The code could be fixed by changing it to:
push 0A000h
pop es
这篇关于内存映射图形输出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！