没啥好说的，总结我电一波实验题目，关于汇编的……
题目要求
实验一EMU8086使用及8086指令系统
·编写一个简单的程序：将“This is my first ASM program-姓名(汉语拼音各人的姓名)”放在DS=1000H，BX=0000H开始的存储器单元中，然后将该内容搬移到BX=0100H开始的单元中，最后将该字符串通过DOS功能调用显示在屏幕上。
实验二 数制转换与数值运算编程
· 2.1将ASCII码表示的十进制数转换为二进制数。
· 2.2BCD码转换为二进制数
· 2.3两个非压缩BCD数加法程序。
· 2.4从键盘上输入任意两个不大于2位数的正整数，计算其乘积。结果在屏幕上显示。
实验三 顺序、分支、循环、子程序设计
·3.1教材P74例1。m=6,n=4,w=7。结果Q也放在内存中。
·3.2教材P75例3。
·3.3从键盘上输入1个数，判断其奇偶性，如果是奇数，屏幕上显示”It is odd”，否则显示”It is even”。
·3.4从键盘上输入N个字符(N<16)，求这N个字符中’A’的个数，并将’A’的个数显示在屏幕上。
·3.5已知BUF1中有N1个按从小到大的顺序排列的互不相等的无符号数，BUF2中有N2个从小到大的顺序排列的互不相等的无符号数。编写程序将BUF1和BUF2中的数合并到BUF3中，使在BUF3中存放的数互不相等且按从小到大的顺序排列。
实验四综合性汇编程序设计
·4.1 计算S＝1＋2×3＋3×4＋4×5＋…＋N(N＋1)，直到N(N＋1)项大于200为止。
·4.2 求N！。N为键盘输入的不大于8的正整数。
·4.3 从键盘输入一行字符(以回车符结束)，并按字母、数字及其它字符分类计数，最后显示出这3个计数结果。
程序清单及结果：
1.
1 name "mycode"
2 org 100h
3 ; set segment register:
4 mov ax, 1000h
5 mov ds, ax
6 mov bx,0000h
7 ; print "This is my first ASM program-WangYuBo"
8 mov [02h], 'T'
9 mov [04h], 'h'
10 mov [06h], 'i'
11 mov [08h], 's'
12 mov [0ah], ' '
13 mov [0ch], 'i'
14 mov [0eh], 's'
15 mov [10h], ' '
16 mov [12h], 'm'
17 mov [14h], 'y'
18 mov [16h], ' '
19 mov [18h], 'f'
20 mov [1ah], 'i'
21 mov [1ch], 'r'
22 mov [1eh], 's'
23 mov [20h], 't'
24 mov [22h], ' '
25 mov [24h], 'A'
26 mov [26h], 'S'
27 mov [28h], 'M'
28 mov [2ah], ' '
29 mov [2ch], 'p'
30 mov [2eh], 'r'
31 mov [30h], 'o'
32 mov [32h], 'g'
33 mov [34h], 'r'
34 mov [36h], 'a'
35 mov [38h], 'm'
36 mov [3ah], '-'
37 mov [3ch], 'W'
38 mov [3eh], 'a'
39 mov [40h], 'n'
40 mov [42h], 'g'
41 mov [44h], 'Y'
42 mov [46h], 'u'
43 mov [48h], 'B'
44 mov [4ah], 'o'
45 mov cx,0025h ;一共37个字符
46 mov bx,0100h
47 mov si,0002h
48 ;string copy
49 copy:
50 mov ax,ds:[si]
51 mov ds:[bx+si],ax
52 add si,2
53 loop copy
54 mov bx,0102h
55 mov cx,0025h
56 ;printf string
57 printf:
58 mov dl,[bx]
59 mov ah,02h
60 int 21h
61 add bx,2
62 loop printf
63 mov ah,1
64 int 21h
65
66 mov ah,4ch
67 int 21h
68 ret
View Code
2.1
1 DATA SEGMENT
2 index DB 30H,30H,32H,35H,36H
3 DATA ENDS
4
5 CODE SEGMENT
6 ASSUME CS:CODE, DS:DATA
7 START:
8 MOV AX, DATA
9 MOV DS, AX
10 MOV SI, OFFSET index
11 MOV CX,5
12 FOR1:
13 MOV AL,[SI]
14 SUB AL,30H
15 MOV [SI],AL
16 INC SI
17 LOOP FOR1
18 MOV AX,0000h
19 MOV BX,0000h
20 LEA SI,index
21
22 MOV DX,10000
23 MOV AL,[SI]
24 IMUL DX
25 MOV BX,AX
26
27 MOV DX,1000
28 INC SI
29 MOV AL,[SI]
30 IMUL DX
31 ADD BX,AX
32
33 MOV DX,100
34 INC SI
35 MOV AL,[SI]
36 IMUL DX
37 ADD BX,AX
38
39 MOV DX,10
40 INC SI
41 MOV AL,[SI]
42 IMUL DX
43 ADD BX,AX
44
45 INC SI
46 MOV AL,[SI]
47 ADD BX,AX
48
49 MOV AX,BX
50
51 ;MOV AX,4C00h
52 ;INT 21h
53
54 CODE ENDS
55 END START
View Code
2.2
1 code segment
2 ASSUME CS:CODE
3 start:
4 ;store data at ds:[3500h]~ds:[3507h]
5 mov si,3500h
6 mov [si],01
7 mov [si+1],02
8 mov [si+2],03
9 mov [si+3],04
10 mov [si+4],05
11 mov [si+5],06
12 mov [si+6],07
13 mov [si+7],08
14 mov cx,4
15 mov di,3510h
16 mov ax,0000h
17 mov bx,000Ah
18 mov dx,0000h
19 for:
20 mov al,ds:[si]
21 imul bl
22 mov dx,ds:[si+1]
23 and dx,00FFh
24 adc ax,dx
25 mov ds:[di],al
26 add si,2
27 inc di
28 loop for
29 mov ax, 4c00h
30 int 21h
31 ends
32 end start
View Code
2.3
1 code segment
2 ASSUME CS:CODE
3 start:
4 mov [0],01010110b ;56h
5 mov [1],00h
6 mov [2],01111000b ;78h 十进制和为134
7 mov [3],00h
8 mov ax,[0] ; ax = 0056h
9 mov bx,[2] ; bx = 0078h
10 mov cx,000Ah
11 mov dx,0000h ;累加和
12 push ax
13 push bx
14 and ax,00F0h
15 and bx,00F0h
16 add ax,bx
17 shr ax,4 ;dx = 000c h
18 imul cx
19 mov dx,ax
20 pop bx
21 pop ax
22 and ax,000Fh
23 and bx,000Fh
24 add ax,bx
25 add dx,ax ;dx store the sum in hex
26 ;----------- print dx with demical number --------
27 mov ax,dx
28 mov cx,0
29 mov bx,10
30 disp1:
31 mov dx,0
32 div bx
33 push dx
34 inc cx
35 or ax,ax
36 jne disp1
37 disp2:
38 mov ah,2
39 pop dx
40 add dl, 30H
41 int 21h
42 loop disp2
43 ;-----------the end------------
44 mov ax,4c00h
45 int 21h
46 ends
47 end start
View Code
2.4
1 data segment
2 str1 db 'please input a number to a:$'
3 str2 db 'please input a number to b:$'
4 str3 db 'result c=a*b=$'
5 a dw ?
6 b dw ?
7 c dw ?
8 data ends
9
10 code segment
11 assume cs:code,ds:data
12 main proc far
13 start:
14 mov ax,data
15 mov ds,ax
16 lea dx,str1 ;ouput str1
17 mov ah,9h
18 int 21h
19 call input ;input a
20 mov a,bx
21 lea dx,str2 ;ouput str2
22 mov ah,9h
23 int 21h
24 call input ;input b
25 mov b,bx
26 lea dx,str3 ;ouput str3
27 mov ah,9h
28 int 21h
29 mov ax,a
30 aad
31 mov bx,ax
32 mov ax,b
33 aad
34 mul bx ;ax = a*b
35 mov word ptr c,ax ;c = a*b
36 mov di,0ah ;di = 10
37 mov cx,0
38 ToTen: ;convert to decimal
39 div di
40 push dx
41 inc cx
42 cmp ax,0
43 je print
44 cwd
45 jmp ToTen
46 print: ;output result
47 pop dx
48 add dl,30h
49 mov ah,2h
50 int 21h
51 loop print
52 ret
53 main endp
54 input proc
55 mov bx,0
56 inputa:
57 mov ah,1 ;first char
58 int 21h
59 sub al,30h
60 mov bl,al
61 mov ah,1 ;second char
62 int 21h
63 cmp al,0dh ;compare if al==Enter
64 je exit
65 sub al,30h
66 mov cl,8 ;shift operation
67 rol bx,cl
68 mov bl,al
69 jmp exit
70 exit:
71 call crlf
72 ret
73 input endp
74 ;print next line
75 crlf proc near
76 mov dl,0ah
77 mov ah,2h
78 int 21h
79 mov dl,0dh
80 mov ah,2h
81 int 21h
82 ret
83 crlf endp
84
85 code ends
86 end start
View Code
3.1
1 data segment
2 address db 06h,04h,07h
3 string1 db ' m=6,n=4,w=7 $'
4 string2 db ' m * n - w = $'
5 data ends
6
7 code segment
8 ASSUME CS:CODE,DS:data
9 main:
10 mov ax,data
11 mov ds,ax
12 mov si,offset address
13 mov al,[si] ;al = m = 6
14 mov bl,[si+1] ;bl = n = 4
15 mul bl ;al = m*n
16 push ax
17 lea dx,string1 ;output string1
18 mov ah,09h
19 int 21h
20 call crlf
21 pop ax
22 mov bx,0 ;bl = 0
23 mov bl,[si+2] ;bl = w = 7
24 sub ax,bx ;ax = m * n - w
25 push ax
26 lea dx,string2 ;output string2
27 mov ah,09h
28 int 21h
29 pop ax
30 ;print demical result
31 mov cx,0
32 mov bx,10
33 disp1:
34 mov dx,0
35 div bx ;如果除数是16位，AX储存商，DX储存余数
36 push dx
37 inc cx
38 or ax,ax
39 jne disp1
40 disp2:
41 mov ah,2
42 pop dx
43 add dl, 30H
44 int 21h
45 loop disp2
46 mov ax,4c00h
47 int 21h
48
49 crlf proc near
50 push dx
51 mov dl,0ah
52 mov ah,2h
53 int 21h
54 mov dl,0dh
55 mov ah,2h
56 int 21h
57 pop dx
58 ret
59 crlf endp
60 code ends
61 end main
View Code
3.2
1 shuju segment
2 DATA db 94,61,86,86,53,84,81,63,45,80,58,81,75,95, 70,85,49,46,85,77,87,99,94,66,78,48,86,65,76,89,74,93,73,100,54,78,75,53,86,50,53,68,63,86,78,62,100,56,48,63,63,52,80,46,100,69,49,95,93,54,75,82,95,51,88,100,82,82,54,96,63,79,66,94,78,81,95,86,95,67
3 BUFFER 4 dup(0)
4 str0 db "The 80 scores are: $"
5 str1 db "#Number of score above 90 points: $"
6 str2 db "#Number of score between 70 points and 89 points: $"
7 str3 db "#Number of score between 60 points and 69 points: $"
8 str4 db "#Number of score above 60 points: $"
9 shuju ends
10
11 code segment
12 assume CS:code,DS:shuju
13 main:
14 mov ax,shuju
15 mov ds,ax
16 mov dx,0000h
17 mov bx,0000h
18 mov cx,80
19 mov si,offset DATA
20 mov di,offset BUFFER
21 nine:
22 mov al,[si]
23 cmp al,90
24 jc eight
25 inc dh
26 jmp stor
27 eight:
28 cmp al,70
29 jc six
30 inc dl
31 jmp stor
32 six:
33 cmp al,60
34 jc five
35 inc bh
36 jmp stor
37 five:
38 inc bl
39 stor:
40 inc si
41 loop nine
42
43 mov [di],dh
44 mov [di+1],dl
45 mov [di+2],bh
46 mov [di+3],bl
47
48 lea dx,str0 ;output string0
49 mov ah,09h
50 int 21h
51 mov cx,80
52 lea si,DATA
53 show:
54 mov ax,0
55 mov al,[si]
56 call printf
57 call space
58 inc si
59 loop show
60 call crlf
61 lea dx,str1
62 mov ah,09h
63 int 21h
64 mov ax,0
65 mov al,[di]
66 call printf
67 call crlf
68 lea dx,str2
69 mov ah,09h
70 int 21h
71 mov ax,0
72 mov al,[di+1]
73 call printf
74 call crlf
75 lea dx,str3
76 mov ah,09h
77 int 21h
78 mov ax,0
79 mov al,[di+2]
80 call printf
81 call crlf
82 lea dx,str4
83 mov ah,09h
84 int 21h
85 mov ax,0
86 mov al,[di+3]
87 call printf
88 call crlf
89 mov ax,4c00h
90 int 21h
91
92 printf proc near
93 push cx
94 push bx
95 push dx
96 mov cx,0
97 mov bx,10
98 disp1:
99 mov dx,0
100 div bx
101 push dx
102 inc cx
103 or ax,ax
104 jne disp1
105 disp2:
106 mov ah,2
107 pop dx
108 add dl,30H
109 int 21h
110 loop disp2
111 ;call crlf
112 pop dx
113 pop bx
114 pop cx
115 ret
116 printf endp
117 crlf proc near
118 push ax
119 push dx
120 mov dl,0ah
121 mov ah,2h
122 int 21h
123 mov dl,0dh
124 mov ah,2h
125 int 21h
126 pop dx
127 pop ax
128 ret
129 crlf endp
130
131 space proc near
132 push ax
133 push dx
134 mov dl,20h
135 mov ah,2h
136 int 21h
137 pop dx
138 pop ax
139 ret
140 space endp
141 code ends
142 end main
View Code
3.3
1 assume cs:code,ds:data
2
3 data segment
4 string0 db 'Welcome to here!Input a number: $'
5 string1 db 'It is odd $'
6 string2 db 'It is even $'
7 string3 db 'Inlegal character!$'
8 data ends
9
10 code segment
11 start:
12 mov ax,data
13 mov ds,ax
14 lea dx,string0 ;output string0
15 mov ah,09h
16 int 21h
17
18 mov cx,10
19 input:
20 mov ah,01h
21 int 21h
22 cmp al,39h
23 ja inlegal
24 cmp al,0dh ;enter \r\n
25 je outside
26 mov bl,al
27 loop input
28 inlegal:
29 call CRLF
30 lea dx,string3 ;output string3
31 mov ah,09h
32 int 21h
33 jmp tail
34 outside:
35 call CRLF
36 and bl,01h
37 cmp bl,1
38 jne even
39 odd:
40 lea dx,string1
41 mov ah,09h
42 int 21h
43 jmp tail
44 even:
45 lea dx,string2
46 mov ah,09h
47 int 21h
48
49 tail:
50 mov ax,4c00h
51 int 21h
52
53 CRLF PROC NEAR
54 PUSH AX
55 PUSH DX
56 MOV DL,0AH
57 MOV AH,2H
58 INT 21H
59 MOV DL,0DH
60 MOV AH,2H
61 INT 21H
62 POP DX
63 POP AX
64 RET
65 CRLF ENDP
66
67 code ends
68 end start
View Code
3.4
1 data segment
2 string1 db 'please input a string: $'
3 string2 db 'the number of char a: $'
4 data ends
5
6 code segment
7 main proc far
8 assume cs:code,ds:data
9 start:
10 mov ax,data
11 mov ds,ax
12 mov cx,16
13 lea dx,string1 ;output string1
14 mov ah,09h
15 int 21h
16 mov dx,0 ;dl store the number of 'a'
17 write:
18 mov ah,1h
19 int 21h
20 cmp al,0dh ;enter \r\n
21 je print
22 cmp al,41h ;'a'
23 jne next
24 inc dl ;dl++
25 next:
26 loop write
27
28 print:
29 call crlf
30 push dx
31 lea dx,string2
32 mov ah,09h
33 int 21h
34 pop dx
35 add dl,30h
36 mov ah,02h
37 int 21h
38
39 mov ax,4c00h
40 int 21h
41 main endp
42
43 crlf proc near
44 push dx
45 mov dl,0ah
46 mov ah,2h
47 int 21h
48 mov dl,0dh
49 mov ah,2h
50 int 21h
51 pop dx
52 ret
53 crlf endp
54 code ends
55 end start
View Code
3.5
1 data segment
2 BUF1 db 1,2,3,5,7,9
3 BUF2 db 0,2,4,6,8
4 BUF3 db 32 dup(204)
5 N1 db 6
6 N2 db 5
7 string db 'Array merged completed!$'
8 data ends
9
10 code segment
11 ASSUME CS:CODE,DS:DATE
12 start:
13 mov ax,data
14 mov ds,ax
15 lea si,BUF1 ;pointer of buffer1
16 lea di,BUF2 ;pointer of buffer2
17 lea bx,BUF3 ;pointer of buffer3
18 mov ax,0
19 mov cx,0
20 mov dx,0
21 mov ah,N1 ;number of N1
22 mov al,N2 ;number of N2
23 mov cl,N1
24 add cl,N2 ;number of N1+N2
25 mov dx,word ptr N2 ;number of N1+N2-1
26 dec dx
27 mov dh,0
28 add dl,ah
29
30 mov ax,word ptr N1 ;number of N1-1
31 dec ax
32 mov ah,0
33 while:
34 cmp si,ax
35 ja b2
36 cmp di,dx
37 ja b1
38 push dx
39 mov dx,[di]
40 cmp [si],dl
41 pop dx
42 ja b2 ;buf1[si] > buf2[di]
43 jb b1 ;buf1[si] < buf2[di]
44 push dx
45 push ax
46 mov dx,[si]
47 mov [bx],dl;buf1[si] == buf2[di]
48 add dl,30h
49 mov ah,2h
50 int 21h
51 pop ax
52 pop dx
53 inc si
54 inc di
55 inc bx
56 dec cx
57 jmp tail
58 b2:
59 push dx
60 push ax
61 mov dx,[di]
62 mov [bx],dl
63 add dl,30h
64 mov ah,2h
65 int 21h
66 pop ax
67 pop dx
68 inc bx
69 inc di
70 jmp tail
71 b1:
72 push dx
73 push ax
74 mov dx,[si]
75 mov [bx],dl
76 add dl,30h
77 mov ah,2h
78 int 21h
79 pop ax
80 pop dx
81 inc bx
82 inc si
83 tail:
84 loop while
85 call crlf
86 lea dx,string
87 mov ah,09h
88 int 21h
89
90 mov ax,4c00h
91 int 21h
92
93 crlf proc near
94 push dx
95 mov dl,0ah
96 mov ah,2h
97 int 21h
98 mov dl,0dh
99 mov ah,2h
100 int 21h
101 pop dx
102 ret
103 crlf endp
104 code ends
105 end start
View Code
4.1
1 data segment
2 string0 db 'Now value of n*(n+1)= 1,and value of S= 1$'
3 string1 db 'Now value of n*(n+1)= $'
4 string2 db ',and value of S= $'
5 string3 db 'Eventually value of S= $'
6 data ends
7 ; calculate 1 + 2*3 + 3*4 + 4*5 +......+n*(n+1) until n*(n+1)>200
8 code segment
9 start:
10 ;-------initialization-------
11 mov ax,data
12 mov ds,ax
13 lea dx,string0
14 mov ah,09h
15 int 21h
16 call crlf
17 mov ax,2 ; ax=2
18 mov bx,ax
19 inc bx ; bx=3 : bx-1 = ax
20 mov cx,15 ; 大概循环15次
21 mov dx,1 ; dx=1 : dx store the value S
22 for:
23 imul bl ; al = n*(n+1)
24 cmp al,200
25 ja outside
26 add dx,ax ; dx = S
27 push bx
28 push cx
29 push dx
30 push ax
31 lea dx,string1
32 mov ah,09h
33 int 21h
34 pop ax
35 call print
36 ;push ax
37 lea dx,string2
38 mov ah,09h
39 int 21h
40 ;pop ax
41 pop dx
42 mov ax,dx
43 push dx
44 call print
45 call crlf
46 pop dx
47 pop cx
48 pop bx
49 mov ax,bx
50 inc bx
51 loop for
52 outside:
53 mov ax,dx
54 push ax
55 lea dx,string3 ;output string3
56 mov ah,09h
57 int 21h
58 pop ax
59 call print
60 mov ax, 4c00h
61 int 21h
62
63 crlf:
64 PUSH AX
65 PUSH DX
66 MOV DL,0AH
67 MOV AH,2H
68 INT 21H
69 MOV DL,0DH
70 MOV AH,2H
71 INT 21H
72 POP DX
73 POP AX
74 RET
75 print:
76 push ax
77 mov cx,0
78 mov bx,10
79 disp1:
80 mov dx,0
81 div bx
82 push dx
83 inc cx
84 or ax,ax
85 jne disp1
86 disp2:
87 mov ah,2
88 pop dx
89 add dl, 30H
90 int 21h
91 loop disp2
92 pop ax
93 ret
94
95 code ends
96 end start
View Code
4.2
1 data segment
2 string0 db 'Welcome to here!Input a number: $'
3 string1 db 'Inlegal character! $'
4 string2 db 'Result of N! = $'
5 data ends
6
7 code segment
8 assume cs:code,ds:data
9 start:
10 mov ax,data
11 mov ds,ax
12 lea dx,string0
13 mov ah,09h
14 int 21h
15 mov ah,01h ;input number N
16 int 21h
17 call CRLF
18 cmp al,38h ; N <= 8
19 ja inlegal
20 cmp al,30h ; N >= 0
21 jb inlegal
22 je part01
23 cmp al,31h
24 je part01
25 sub al,30h
26 mov cx,0
27 mov cl,al
28 dec cl ;cx = N-1
29 mov ax,1
30 mov bx,2
31 mov dx,0 ; store the value of N!
32 mul:
33 imul bx
34 mov dx,ax
35 inc bx
36 loop mul
37 push dx ; dx = N!
38 lea dx,string2
39 mov ah,09h
40 int 21h
41 pop ax ; ax = N!
42 call print
43 tail:
44 mov ax, 4c00h
45 int 21h
46 part01:
47 lea dx,string2
48 mov ah,09h
49 int 21h
50 mov ax,1
51 call print
52 jmp tail
53 inlegal:
54 lea dx,string1 ;output string1
55 mov ah,09h
56 int 21h
57 jmp tail
58 print:
59 push ax
60 mov cx,0
61 mov bx,10
62 disp1:
63 mov dx,0
64 div bx
65 push dx
66 inc cx
67 or ax,ax
68 jne disp1
69 disp2:
70 mov ah,2
71 pop dx
72 add dl,30H
73 int 21h
74 loop disp2
75 pop ax
76 ret
77 CRLF:
78 PUSH AX
79 PUSH DX
80 MOV DL,0AH
81 MOV AH,2H
82 INT 21H
83 MOV DL,0DH
84 MOV AH,2H
85 INT 21H
86 POP DX
87 POP AX
88 RET
89 ends
90 end start
View Code
4.3
1 data segment
2 string0 db ' Welcome to here!Input a string: $'
3 string1 db '**********Count of alphabet: $'
4 string2 db '**********Count of number: $'
5 string3 db '**********Count of other character: $'
6 count_alph db 0
7 count_num db 0
8 count_char db 0
9 ends
10
11 code segment
12 assume cs:code,ds:data
13 start:
14 mov ax, data
15 mov ds, ax
16 lea si,count_alph
17 lea dx,string0 ;output string0
18 mov ah,09h
19 int 21h
20 mov cx,40
21 input:
22 mov ah,01h
23 int 21h
24 cmp al,0dh ;enter \r\n
25 je printf_count
26 cmp al,48 ;'0'
27 jb add_char
28 cmp al,58 ;'9'+1
29 jb add_num
30 cmp al,65 ;'A'
31 jb add_char
32 cmp al,91 ;'Z'+1
33 jb add_alph
34 cmp al,97 ;'a'
35 jb add_char
36 cmp al,123 ;'z'+1
37 jb add_alph
38 jmp add_char
39 inside:
40 loop input
41 printf_count:
42 call crlf
43 call crlf
44 lea dx,string1 ;output string1
45 mov ah,09h
46 int 21h
47 mov al,[si]
48 mov ah,0
49 call print
50 call crlf
51 call crlf
52 lea dx,string2 ;output string2
53 mov ah,09h
54 int 21h
55 mov al,[si+1]
56 mov ah,0
57 call print
58 call crlf
59 call crlf
60 lea dx,string3 ;output string3
61 mov ah,09h
62 int 21h
63 mov al,[si+2]
64 mov ah,0
65 call print
66 tail:
67 mov ax, 4c00h
68 int 21h
69 crlf:
70 PUSH AX
71 PUSH DX
72 MOV DL,0AH
73 MOV AH,2H
74 INT 21H
75 MOV DL,0DH
76 MOV AH,2H
77 INT 21H
78 POP DX
79 POP AX
80 RET
81 print:
82 push ax
83 mov cx,0
84 mov bx,10
85 disp1:
86 mov dx,0
87 div bx
88 push dx
89 inc cx
90 or ax,ax
91 jne disp1
92 disp2:
93 mov ah,2
94 pop dx
95 add dl, 30H
96 int 21h
97 loop disp2
98 pop ax
99 ret
100 add_alph:
101 push dx
102 mov dl,[si]
103 inc dl
104 mov [si],dl
105 pop dx
106 jmp inside
107 add_num:
108 push dx
109 mov dl,[si+1]
110 inc dl
111 mov [si+1],dl
112 pop dx
113 jmp inside
114 add_char:
115 push dx
116 mov dl,[si+2]
117 inc dl
118 mov [si+2],dl
119 pop dx
120 jmp inside
121 ends
122 end start
View Code
上面很多题目都涉及到了dos输出，其实还挺有意思的。下面的代码是把ax寄存器中保存的十六进制值打印出来的函数printf：
code segment
start:
mov ax,245
call printf
mov ax,1234
call printf
mov ax,2222
call printf
mov ax, 4c00h
int 21h
printf proc near
push cx
push bx
push dx
mov cx,0
mov bx,10
disp1:
mov dx,0
div bx ;如果除数是16位，AX储存商，DX储存余数
push dx
inc cx
or ax,ax
jne disp1 ;ax!=0 then jump to disp1
disp2: ;stack top 2-4-5 stack bottom ,cx=3 means 3 elements in stack
mov ah,2
pop dx
add dl, 30H ;print :02h->32h ('2') 04h->34h ('4') 05h->35h ('5')
int 21h
loop disp2
call crlf
pop dx
pop bx
pop cx
ret
printf endp
crlf proc near
push ax
push dx
mov dl,0ah
mov ah,2h
int 21h
mov dl,0dh
mov ah,2h
int 21h
pop dx
pop ax
ret
crlf endp
code ends
end start
输入一个小于100的正整数(两位以内)用了input函数，关键在于指令aad：
code segment
start:
mov ax,0
call input
mov ax,bx
aad
call printf
mov ax, 4c00h ; exit to operating system.
int 21h
printf proc near
push cx
push bx
push dx
mov cx,0
mov bx,10
disp1:
mov dx,0
div bx ;如果除数是16位，AX储存商，DX储存余数
push dx
inc cx
or ax,ax
jne disp1 ;ax!=0 then jump to disp1
disp2: ;stack top 2-4-5 stack bottom ,cx=3 means 3 elements in stack
mov ah,2
pop dx
add dl, 30H ;print :02h->32h ('2') 04h->34h ('4') 05h->35h ('5')
int 21h
loop disp2
call crlf
pop dx
pop bx
pop cx
ret
printf endp
input proc
mov bx,0
mov ah,1 ;first char
int 21h
sub al,30h
mov bl,al
mov ah,1 ;second char
int 21h
cmp al,0dh ;compare if al==Enter
je exit
sub al,30h
mov cl,8 ;shift operation
rol bx,cl
mov bl,al
jmp exit
exit:
call crlf
ret
input endp
crlf proc near
mov dl,0ah
mov ah,2h
int 21h
mov dl,0dh
mov ah,2h
int 21h
ret
crlf endp
ends
end start
