实验一
代码:
assume cs:code, ds:data data segment x dw 1020h, 2240h, 9522h, 5060h, 3359h, 6652h, 2530h, 7031h y dw 3210h, 5510h, 6066h, 5121h, 8801h, 6210h, 7119h, 3912h data ends code segment start: mov ax, data mov ds, ax mov si, offset x mov di, offset y call add128 mov ah, 4ch int 21h add128: push ax push cx push si push di sub ax, ax mov cx, 8 s: mov ax, [si] adc ax, [di] mov [si], ax inc si inc si inc di inc di loop s pop di pop si pop cx pop ax ret code ends end star
① line31~line34的4条inc指令,能否替换成如下代码?你的结论的依据是什么?
不能,add会影响进位标志符CF,而inc则不会改变CF的值
实验二
代码:
assume cs:code, ds:data data segment str db 80 dup(?) data ends code segment start: mov ax, data mov ds, ax mov si, 0 s1: mov ah, 1 int 21h mov [si], al cmp al, '#' je next inc si jmp s1 next: mov ah, 2 mov dl, 0ah int 21h mov cx, si mov si, 0 s2: mov ah, 2 mov dl, [si] int 21h inc si loop s2 mov ah, 4ch int 21h code ends end start
① 汇编指令代码line11-18,实现的功能是?
接收输入字符并保存到ds段中,直到输入字符为‘#’且不包含‘#’
② 汇编指令代码line20-22,实现的功能是?打印换行符号
③ 汇编指令代码line24-30,实现的功能是?打印出ds中的字符
实验三
代码:
assume cs:code,ds:data,ss:stack data segment x dw 91, 792, 8536, 65521, 2021 len equ $ - x data ends stack segment dw 8 dup(0) stack ends code segment start: mov ax, data mov ds, ax mov si, offset x mov ax, stack mov ss, ax mov sp, 16 mov cx, len/2 mov bx, 10 s: mov ax, word ptr ds:[si] push cx call printNumber call printSpace add si,2 pop cx loop s mov ax, 4c00h int 21h printNumber: mov cx, 0 s1: mov dx, 0 div bx push dx inc cx or ax,0 jnz s1 s2: pop dx add dl, 30h mov ah, 2 int 21h loop s2 ret printSpace: mov ah, 2 mov dl, ' ' int 21h ret code ends end start
实验四
代码:
assume cs:code,ds:data data segment str db "assembly language, it's not difficult but tedious" len equ $ - str data ends stack segment db 8 dup(?) stack ends code segment start: mov ax, data mov ds, ax mov si, 0 mov cx, len call strupr call printStr mov ax, 4c00h int 21h strupr : push cx push si transform: mov al, ds:[si] cmp al, 97 jl continue cmp al, 122 jg continue and al, 0dfh mov ds:[si], al continue: inc si loop transform pop si pop cx ret printStr: push cx push si print: mov ah, 2 mov dl, ds:[si] int 21h inc si loop print pop si pop cx ret code ends end start
实验五
代码:
assume cs:code, ds:data data segment str1 db "yes", '$' str2 db "no", '$' data ends code segment start: mov ax, data mov ds, ax mov ah, 1 int 21h mov ah, 2 mov bh, 0 mov dh, 24 mov dl, 70 int 10h cmp al, '7' je s1 mov ah, 9 mov dx, offset str2 int 21h jmp over s1: mov ah, 9 mov dx, offset str1 int 21h over: mov ah, 4ch int 21h code ends end start
实验六
代码:
assume cs:code code segment start: ; 42 interrupt routine install code mov ax, cs mov ds, ax mov si, offset int42 ; set ds:si mov ax, 0 mov es, ax mov di, 200h ; set es:di mov cx, offset int42_end - offset int42 cld rep movsb ; set IVT(Interrupt Vector Table) mov ax, 0 mov es, ax mov word ptr es:[42*4], 200h mov word ptr es:[42*4+2], 0 mov ah, 4ch int 21h int42: jmp short int42_start str db "welcome to 2049!" len equ $ - str ; display string "welcome to 2049!" int42_start: mov ax, cs mov ds, ax mov si, 202h mov ax, 0b800h mov es, ax mov di, 24*160 + 32*2 mov cx, len s: mov al, [si] mov es:[di], al mov byte ptr es:[di+1], 2 inc si add di, 2 loop s iret int42_end: nop code ends end start
assume cs:code code segment start: int 42 mov ah, 4ch int 21h code ends end start
代码:
assume cs:code code segment start: int 42 mov ah, 4ch int 21h code ends end start