王爽<汇编语言> 第十章 实验十

assume cs:codesg,ds:datasg,ss:stacksg



datasg segment

db 2h ;绿色 ;0h

db 24h ;绿底红色 ;1h

db 71h ;白底蓝色 ;2h

db 'welcome to masm!',0 ;text ;3h

db 16 dup(0) ;13h

datasg ends



stacksg segment

dd 16 dup (0)

stacksg ends



codesg segment

;--------------------------------------------------------showStr-------------------------------------------------------------------------------

showStr:push bp;(byte->height(+9h)_byte->width(+8h),byte_byte->color(+6h),word->text_addr(+4h))(无返回,已恢复栈)

mov bp,sp

push ax

push bx

push cx

push dx

push di

push si

;计算所在行数

mov al,ss:9h[bp];获取行数

mov bl,160;每行160个字节

mul bl;行数x每行字节数

push ax;保存下结果

;计算所在列数

mov al,ss:8h[bp];获取列数

mov bl,2h;你懂的...

mul bl;

pop bx

add ax,bx;定位显存位置

mov si,ax;保存一下

;显示

mov di,0

mov bx,ss:4h[bp]

mov ax,0b800h

mov es,ax

for1:mov cl,ds:[bx][di];循环每个字符,复制到显示缓冲区,并加上色

mov ch,0

jcxz return

mov byte ptr es:[si],cl;复制字符

inc si

mov ch,ss:6h[bp];获取颜色参数

mov byte ptr es:[si],ch;设置颜色

inc si

inc di

loop for1

return:pop si

pop di

pop dx

pop cx

pop bx

pop ax

pop bp

ret 6h

;--------------------------------------------------------showStr-------------------------------------------------------------------------------

;--------------------------------------------------------divdw---------------------------------------------------------------------------------

divdw:push bp;(word->dividl(+8h),word->dividh(+6h),word->divish(+4h))(有返回(pop(+4h余),pop(+6h结果高位),pop(+8h结果低位)),自行恢复栈)

mov bp,sp

push ax

push bx

push cx

push dx

mov dx,0

mov ax,ss:6h[bp]

div word ptr ss:4h[bp]

mov word ptr ss:6h[bp],ax;32位结果的高位

mov ax,word ptr ss:8h[bp]

div word ptr ss:4h[bp];欧几里德同余公式,被搞死...郁闷

mov word ptr ss:8h[bp],ax;32位结果的底位

mov word ptr ss:4h[bp],dx;32位结果的余

pop dx

pop cx

pop bx

pop ax

pop bp

ret

;--------------------------------------------------------divdw---------------------------------------------------------------------------------

;--------------------------------------------------------dtoc----------------------------------------------------------------------------------

dtoc:push bp;(word->numl(+8h),word->numh(+6h),word->txt_addr(+4h))(无返回,已恢复栈)

mov bp,sp

push di

push ax

push dx

push bx

push cx

push si

mov si,0;转换计数

mov di,ss:4h[bp];获取存放字符串的地址

mov ax,ss:8h[bp];获取被除数低位

push ax

mov ax,ss:6h[bp];获取被除数高位

push ax

mov ax,10;设置除数

push ax

call divdw

pop cx

pop dx

pop ax

jmp dtoc_go

dtoc_to:push ax

push dx

mov ax,10

push ax

call divdw

pop cx

pop dx

pop ax

dtoc_go:add cx,30h;数字转字符

push cx;保存结果

inc si

mov cx,ax;先检查结果的低位等不等于0

jcxz dtoc_ch;如果等于转到dtoc_ch检查高位

jmp dtoc_to;否则继续转换

dtoc_ch:mov cx,dx;检查高位等不等于0

jcxz dtoc_fl;高位和低位都为0,除完...你懂的

jmp dtoc_to;不用看了,继续转吧...

dtoc_fl:mov cx,si

jcxz dtoc_f

dtoc_l1:pop ax

mov ds:[di],al;设置正确结果

inc di

loop dtoc_l1

dtoc_f:pop si

pop cx

pop bx

pop dx

pop ax

pop di

pop bp

ret 6h

;--------------------------------------------------------dtoc----------------------------------------------------------------------------------

start:mov ax,datasg

mov ds,ax



mov ax,stacksg

mov ss,ax

mov sp,40h



mov ah,20

mov al,33

push ax

mov ah,0

mov al,71h

push ax

mov ax,3h

push ax

call showStr



mov ax,4240h

push ax

mov ax,000fh

push ax

mov ax,0ah

push ax

call divdw

pop cx

pop dx

pop ax



mov ax,123

push ax

mov ax,0

push ax

mov ax,13h

push ax

call dtoc



mov ax,4c00h

int 21h

codesg ends



end start