.8086
.MODEL SMALL
.DATA
ORG 100H;CS起始地址
STR DB 20,0,20 DUP(20H);字符串STR
.CODE
START:
	MOV AX,@DATA
	MOV DS,AX;数据段地址
	LEA DX,STR;将STR的相对于数据段首地址的偏移地址放进DX
	MOV AH,0AH
	INT 21H;从键盘输入一个字符串
	
	MOV DL,0AH
	MOV AH,02
	INT 21H;输出DL中的换行
	MOV DL,0DH
	MOV AH,02
	INT 21H;输出回车
	
	MOV BL,STR[1]
	MOV BH,0;BX=20
	MOV BYTE PTR STR[BX+2],'$';末尾加'$'
	LEA DX,STR+2
	MOV AH,9
	INT 21H;输出这一句话
	MOV AH,4CH
	INT 21H;返回DOS
END START

.8086
.MODEL SMALL
.STACK
.DATA
    Table BYTE 0,1,4,9,16,25,36,49,64,81
    XX BYTE 9
    YY BYTE ?
.CODE
START:
    MOV AX,@DATA
    MOV DS,AX
    LEA BX,Table
    MOV AL,XX
    XLAT;以DS:[BX+AL]为地址，提取存储器中的一个字节再送入AL。
    MOV YY,AL
END START

.8086
.MODEL SMALL
.STACK
.DATA
    N EQU 20
    MAXLEN BYTE N
    ACTLEN BYTE ?
    STRING BYTE N DUP('$')
    TRUE BYTE 0AH,0DH,'It is a palindrome',0AH,0DH,'$'	;开头加0AH、0DH是为了防止回车把输入冲掉
    FALSE BYTE 0AH,0DH,'It is NOT a palindrome',0AH,0DH,'$'
.CODE
START:
    MOV AX,@DATA
    MOV DS,AX
    MOV AH,0AH
    MOV DX,OFFSET MAXLEN
    INT 21H;缓冲区的第一个字节指定容纳的最大字符个数，由用户给出；第二个字节存放实际的最大字符个数，由系统最后填入；从第三个字节开始存放从键盘接受的字符，直到ENTER键结束。
    MOV AL,ACTLEN
    MOV AH,0
    MOV BL,2
    DIV BL
    CMP AH,1
    JE ITSODD;如果是奇数字数的字符串，跳到"It's odd"
    CMP AL,1
    JE ITSTWO;如果是两个字符的字符串，跳到"It's two"
    ADD AL,AH;奇数个数和偶数个数的区别就在这句话
    MOV AH,0
    MOV BL,ACTLEN
    MOV BH,0
    MOV SI,BX
    MOV BX,OFFSET STRING
    DEC SI
ITSEVEN:
    CMP SI,AX
    JNA T
    MOV DL,[BX+SI]
    MOV DH,[BX]
    CMP DL,DH
    JNZ F
    INC BX
    SUB SI,2;因为BX加了一，所以BX+SI要想减一，就需要SI减二
    JMP ITSEVEN
ITSODD:
    MOV AH,0
    MOV BL,ACTLEN
    MOV BH,0
    MOV SI,BX
    MOV BX,OFFSET STRING
    DEC SI
JUDGEODD:
    CMP SI,AX
    JNA T
    MOV DL,[BX+SI]
    MOV DH,[BX]
    CMP DL,DH
    JNZ F
    INC BX
    SUB SI,2
    JMP JUDGEODD
ITSTWO:
    MOV BX,OFFSET STRING
    MOV DL,[BX+1]
    MOV DH,[BX]
    CMP DL,DH
    JNE F;如果这两个字符不相同，就不是。否则直接向下执行T
T:  MOV DX,OFFSET TRUE
    JMP QUIT
F:  MOV DX,OFFSET FALSE
    JMP QUIT
QUIT:
    MOV AH,09H
    INT 21H
    MOV AH,4CH
    INT 21H
END START

.8086
.MODEL SMALL
.STACK
.DATA
    BUFF BYTE 0,1,2,3,4,5,6,7,8,9
.CODE
START:
    MOV AX,@DATA
    MOV DS,AX
    MOV CX,10;计数初始化为10
    LEA SI,BUFF;BUFF首地址给SI
    MOV AH,01H
    INT 21H;从键盘输入一个字符
    SUB AL,30H;将ASCII码变成数字
    MOV AH,0
NEXT:
    MOV BL,[SI]
    MOV BH,0
    CMP AX,BX
    JE DEL;找到了就跳至删除
    INC SI
    LOOP NEXT
    JMP STOP;找不到就停
DEL:
    MOV DI,SI;记住当前元素的位置
    INC SI
    MOV AL,[SI]
    MOV AH,0
    MOV [DI],AX;后面的内容前移
    LOOP DEL
    MOV [SI],0;找到的最后一位换成0
    LEA SI,BUFF;SI指向BUFF首地址
    MOV CX,9;设计数器为9
    MOV AH,02H
    MOV DL,0DH
    INT 21H;回车
    MOV DL,0AH
    INT 21H;换行
DO:
    MOV DL,[SI]
    MOV DH,0
    ADD DX,3030H;十六进制转ASCII
    INC SI
    INT 21H;一个个输出此时BUFF内容
    LOOP DO
STOP:
    MOV AH,4CH
    INT 21H;退回DOS
END START

.8086
.MODEL SMALL
.STACK
.DATA
    STRING DB 'You must input 0~9, OR `Q` OR `q`',0AH,0DH,'$'
    BUF DB 8 DUP(30H),'$'
.CODE
START:
    MOV AX,@DATA
    MOV DS,AX
    MOV AH,01H
    INT 21H
    CMP AL,'q'
    JE EXIT
    CMP AL,'Q'
    JE EXIT;输入'q'或'Q'时退出
    CMP AL,'0'
    JL WRONG
    CMP AL,'9'
    JG WRONG;输入小于零或者大于九时错误
    
    MOV BL,AL
    MOV AH,02H
    MOV DL,0DH
    INT 21H
    MOV DL,0AH
    INT 21H;回车换行
    
    MOV AL,BL
    SUB AL,30H;ASCII码转数字
    MOV DX,0
    MOV AH,0
    MOV BX,OFFSET BUF+7
AGAIN:
    MOV DX,0;余数清零
    MOV CX,2
    DIV CX
    ADD DL,30H;转ASCII码
    MOV [BX],DL;将零或一附给BX所指内存中的元素
    DEC BX;向左移一位
    AND AX,AX
    JNE AGAIN;AX不为零就继续循环
    JMP RIGHT;其实这句可有可无，当时随便就写上了
RIGHT:
    MOV AH,09H
    LEA DX,BUF
    INT 21H;输出BUF内容
    JMP EXIT
WRONG:
    MOV AH,09H
    LEA DX,STRING
    INT 21H;输出STRING内容
    JMP EXIT
EXIT:
    MOV AH,4CH
    INT 21H;退出到DOS
END START

.8086
.MODEL SMALL
.STACK
.DATA
    STRING BYTE 6 DUP(20H),'$'
    ENDL BYTE 0AH,0DH,'$'
    ERRMSG BYTE 'You must input a number from 1~6',0AH,0DH,'$'
.CODE
START:
    MAIN PROC
    MOV AX,@DATA
    MOV DS,AX
    MOV AH,01H
    INT 21H
    CMP AL,'1'
    JL ERR;小于1的ASCII码错误
    CMP AL,'6'
    JG ERR;大于6的ASCII码错误
    SUB AL,30H
    MOV CL,AL
    LEA DX,ENDL
    MOV AH,09H
    INT 21H
    MOV DX,0
    LEA BX,STRING+5
    MOV AL,01H
    MOV AH,0
    MOV CH,0
    CALL DAC
    CALL PRINT
    MAIN ENDP
    
    DAC PROC
AGAIN:
    MOV DX,CX
    MUL DX
    LOOP AGAIN
    DAC ENDP
    
    PRINT PROC
    MOV CX,10
DO:
    MOV DX,0
    DIV CX
    ADD DL,30H
    DEC BX
    MOV [BX],DL
    AND AX,AX
    JNE DO
    MOV DX,BX
    MOV AH,09H
    INT 21H
    MOV AH,4CH
    INT 21H
    PRINT ENDP
    
ERR:
    LEA DX,ENDL
    MOV AH,09H
    INT 21H
    LEA DX,ERRMSG
    MOV AH,09H
    INT 21H
    MOV AH,4CH
    INT 21H
END START

.8086
.MODEL SMALL
EXTRA SEGMENT
    ARRAY BYTE 10,1,2,3,4,5,6,7,8,9,10
EXTRA ENDS
.CODE
ASSUME ES:EXTRA
START:
    MOV BX,EXTRA
    MOV ES,BX
    LEA DI,ES:ARRAY
    
    MOV AL,7
    
    MOV CX,0
    MOV CL,ES:[DI]
    INC DI
    MOV DX,DI
    ADD DX,CX
    MOV SI,DX
    MOV DX,0
    
    CMP AL,ES:[DI]
    MOV BX,DI
    JB NOTFOUND
    JE FOUND
    CMP AL,ES:[SI-1]
    MOV BX,SI
    JA NOTFOUND
    JE FOUND

WORK:
    MOV BX,DI
    ADD BX,SI
    SHR BX,1
    CMP AL,ES:[BX]
    JZ FOUND
    PUSHF
    CMP BX,DI
    JZ NOTFOUND
    POPF
    JL LESS
    MOV DI,BX
    JMP WORK
LESS:
    MOV SI,BX
    JMP WORK
NOTFOUND:
    STC
    JMP EXIT
FOUND:
    CLC
    MOV BX,SI
    JMP EXIT
EXIT:
    MOV AH,4CH
    INT 21H
END START

.8086
.MODEL SMALL
.STACK
.DATA
    SCORE DB 85,73,92,66,91,98,52,87,83,68
    ENDL DB 0AH,0DH,'$'
.CODE
START:
    MOV AX,@DATA
    MOV DS,AX
    MOV DI,OFFSET SCORE
    MOV AX,0
    MOV BX,0
    MOV CX,09H
    MOV DX,0
C1:
    MOV DX,CX
    MOV DI,OFFSET SCORE
C2:
    MOV AL,[DI]
    MOV BL,[DI+1]
    CMP AL,BL
    JB CHANGE
    JMP NEXT
CHANGE:
    MOV [DI],BL
    MOV [DI+1],AL
NEXT:
    INC DI
    LOOP C2
    MOV CX,DX
    LOOP C1
    
    MOV CX,10
    MOV DI,OFFSET SCORE
PRINT:
    MOV AH,0
    MOV AL,[DI]
    MOV BL,10
    DIV BL
    MOV DX,AX
    ADD DX,3030H
    MOV AH,02H
    INT 21H
    MOV DL,DH
    INT 21H
    MOV DX,OFFSET ENDL
    MOV AH,09H
    INT 21H
    INC DI
    LOOP PRINT
    MOV AH,4CH
    INT 21H
END START