简介
使用跳转表实现10进制->16进制、16进制->10进制、2进制->10进制转换，及10进制乘除法。
程序运行结果
代码
ASSUME CS:CODE1,DS:DATA1,SS:STACK1
STACK1 SEGMENT STACK
STACK_AREA DW 200H DUP(?)
STACK_BTM EQU $-STACK_AREA
STACK1 ENDS
DATA1 SEGMENT
EXPLAIN DB 13,10,"please select function: 1. HEX TO DEC 2.DEC TO HEX 3.BIN TO DEC 4.DEC MUL 5.DEC DIV other.QUIT",13,10,'$'
EXPLAIN_INPUT DB 13,10,"please input number",13,10,'$'
NUMBER DD 1235H
ASCII DB 20H DUP(0)
;跳转表
FUNC_TABLE DW HEX2DEC,DEC2HEX,BIN2DEC,DEC_MUL,DEC_DIV
DATA1 ENDS
CODE1 SEGMENT
OUTPUT_NUM PROC NEAR ;[SP+2]:num(byte)
PUSH BP
MOV BP,SP
PUSH AX
PUSH DX
MOV DL,[BP+4]
CMP DL,9
JA OUTPUT_NUM_ALPHA
ADD DL,'0'
JMP OUTPUT_NUM_OUTPUT
OUTPUT_NUM_ALPHA:
ADD DL,'A'-10
OUTPUT_NUM_OUTPUT:
MOV AH,02H
INT 21H
POP DX
POP AX
POP BP
RET 2
OUTPUT_NUM ENDP
MAIN PROC FAR
MOV AX,STACK1
MOV SS,AX
MOV SP,STACK_BTM
MOV AX,DATA1
MOV DS,AX
MAIN_LOOP:
MOV DX,OFFSET EXPLAIN
MOV AH,09H
INT 21H
MOV AH,01H
INT 21H
CMP AL,'1'
JB EXIT
CMP AL,'5'
JA EXIT
SUB AL,'1'
MOV AH,0
MOV BX,AX
SHL BX,1
MOV DX,OFFSET EXPLAIN_INPUT
MOV AH,09H
INT 21H
MOV SI,OFFSET FUNC_TABLE
JMP [SI+BX]
CONTINUE:
JMP MAIN_LOOP
EXIT:
MOV AH,4CH
INT 21H
DEC_MUL:
CALL READ_DEC
PUSH AX
CALL READ_DEC
POP BX
MUL BX
MOV BX,AX
JMP DEC_MUL_OUTPUT
JMP CONTINUE
DEC_DIV:
CALL READ_DEC
PUSH AX
CALL READ_DEC
MOV BX,AX
POP AX
MOV DX,0
DIV BX
MOV BX,AX
JMP DEC_MUL_OUTPUT
JMP CONTINUE
DEC2HEX:
MOV BX,0
DEC2HEX_LOOP:
MOV AH,01
INT 21H
CMP AL,'0'
JB DEC2HEX_LOOP_END
CMP AL,'9'
JA DEC2HEX_LOOP_END
SUB AL,'0'
MOV AH,0
PUSH AX
MOV AX,BX
MOV BX,10
MUL BX
MOV BX,AX
POP AX
ADD BX,AX
JMP DEC2HEX_LOOP
DEC2HEX_LOOP_END:
MOV CX,4
DEC2HEX_LOOP2:
ROL BX,1
ROL BX,1
ROL BX,1
ROL BX,1
MOV DL,BL
AND DL,0FH
PUSH DX
CALL OUTPUT_NUM
LOOP DEC2HEX_LOOP2
MOV AX,BX
JMP CONTINUE
JMP CONTINUE
BIN2DEC:
MOV BX,0
BIN2DEC_LOOP:
MOV AH,01
INT 21H
CMP AL,'0'
JB BIN2DEC_LOOP_END
CMP AL,'1'
JA BIN2DEC_LOOP_END
SUB AL,'0'
MOV AH,0
SHL BX,1
ADD BX,AX
JMP BIN2DEC_LOOP
BIN2DEC_LOOP_END:
JMP BIN2DEC_LOOP2_INIT
HEX2DEC:
MOV BX,0
HEX2DEC_LOOP:
MOV AH,01
INT 21H
CMP AL,'0'
JB HEX2DEC_LOOP_END
CMP AL,'9'
JA HEX2DEC_ASCII
SUB AL,'0'
JMP HEX2DEC_READ
HEX2DEC_ASCII:
OR AL,32
CMP AL,'a'
JB HEX2DEC_LOOP_END
CMP AL,'f'
JA HEX2DEC_LOOP_END
SUB AL,'a'-10
HEX2DEC_READ:
SHL BX,1
SHL BX,1
SHL BX,1
SHL BX,1
MOV AH,0
ADD BX,AX
JMP HEX2DEC_LOOP
HEX2DEC_LOOP_END:
BIN2DEC_LOOP2_INIT:
DEC_MUL_OUTPUT:
MOV AX,BX
MOV SI,10
MOV DI,0
MOV BP,OFFSET ASCII
HEX2DEC_LOOP2:
MOV DX,0
MOV CX,10
DIV CX
; ADD DL,'0'
MOV DS:[BP+DI],DL
INC DI
CMP AX,0
JNE HEX2DEC_LOOP2
MOV CX,DI
HEX2DEX_LOOP3:
DEC DI
MOV DL,DS:[BP+DI]
PUSH DX
CALL OUTPUT_NUM
LOOP HEX2DEX_LOOP3
MOV AX,BX
JMP CONTINUE
MAIN ENDP
；读取一个10进制数，并通过AX返回。由于使用次数较多，写成函数比较方便
READ_DEC PROC NEAR
MOV BX,0
READ_DEC_LOOP:
MOV AH,01
INT 21H
CMP AL,'0'
JB READ_DEC_LOOP_END
CMP AL,'9'
JA READ_DEC_LOOP_END
SUB AL,'0'
MOV AH,0
PUSH AX
MOV AX,BX
MOV BX,10
MUL BX
MOV BX,AX
POP AX
ADD BX,AX
JMP READ_DEC_LOOP
READ_DEC_LOOP_END:
MOV AX,BX
RET
READ_DEC ENDP
CODE1 ENDS
END MAIN
