5-6.asm

这是一个用汇编语言编写的一个菜单选择程序

data       segment
menu        db       0dh,0ah,"1.欢迎光临  2.谢谢再次光临"
            db       "3.您好，老朋友 0.再见"
            db       "请选择：$"
errmsg      db       0dh,0ah,"选择有误,请重新选择!$"
sel0        db       0dh,0ah,"您选择了0,BYE-BYE!$"
sel1        db       0dh,0ah,"您选择了1,WELCOME!$"
sel2        db       0dh,0ah,"您选择了2,THANK YOU!$"
sel3        db       0dh,0ah,"您选择了3,HOW ARE YOU!$"
addrtab     dw       a0,a1,a2,a3
data        ends
code        segment
            assume   ds:data,cs:code
start:      mov      ax,data
            mov      ds,ax
again:      lea      dx,menu
            mov      ah,9
            int      21h
            mov      ah,1
            int      21h
            cmp      al,'0'
            jb       error
            lea      bx,addrtab
            sub      al,30h
            shl      al,1
            xor      ah,ah
            add      bx,ax
            jmp      word ptr [bx]
error:      mov      dx,offset errmsg
            mov      ah,9
            int      21h
            jmp      again
a0:         lea      dx,sel0
            mov      ah,9
            int      21h
            jmp      done
a1:         lea      dx,sel1
            mov      ah,9
            int      21h
            jmp      again
a2:         lea      dx,sel2
            mov      ah,9
            int      21h
            jmp      again
a3:         lea      dx,sel3
            mov      ah,9
            int      21h
            jmp      again
done:       mov      ah,4ch
            int      21h
code        ends
            end      start