rjexp2.asm

显示屏相关程序实现显示屏点亮控制等功能.

DATA SEGMENT
DATA1 DB     32H,39H,30H,35H,34H
DATA2 DB     34H
MES1  DB     '*','$'
MES2  DB     '=','$'
RESULT DB     6 DUP (00H)
DATA ENDS
STACK SEGMENT
STA  DB     20 DUP (?)
TOP  EQU    LENGTH  STA
STACK ENDS
CODE SEGMENT
ASSUME CS:CODE,DS:DATA,SS:STACK,ES:DATA
START:  MOV     AX,DATA
        MOV     DS,AX
        MOV     AX,STACK
        MOV     SS,AX 
        MOV     SP,TOP
        LEA     SI,DATA1
        MOV     BX,05H
  L1:   MOV     AH,02H
        MOV     DL,[SI+BX-1]
        INT     21H
        DEC     BX    
        JNZ     L1
        MOV     AH,09H
        LEA     DX,MES1
        INT     21H
        LEA     SI,DATA2
        MOV     AH,02H
        MOV     DL,[SI]
        INT     21H
        MOV     AH,09H
        LEA     DX,MES2
        INT     21H
        MOV     SI,OFFSET DATA2 ;显示算式
        MOV     BL,[SI]         ;乘数DATA2→BL
        AND     BL,00001111B    ;屏蔽高4位,ASCII码转化为十六进制数
        MOV     SI,OFFSET DATA1
        MOV     DI,OFFSET RESULT
        MOV     CX,05
LOOP1:  MOV     AL,[SI]
        AND     AL,00001111B    ;取被乘数DATA1,ASCII变十六进制数
        INC     SI              ;指向被乘数1的下一字符单元
        MUL     BL              ;相乘
        AAM                     ;AAM调整
        ADD     AL,[DI]         ;结果低位与前次计算的进位相加
        AAA                     ;AAA调整
        MOV     [DI],AL
        INC     DI              ;结果送存到下一单元
        MOV     [DI],AH
        LOOP    LOOP1           ;计算结果高位进位送存
        MOV     CX,06
        MOV     SI,DI 
DISPL:  MOV     AH,02
        MOV     DL,[SI]
        ADD     DL,30H
        INT     21H
        DEC     SI
        LOOP    DISPL          ;显示结果
        MOV     AX,4C00H      
        INT     21H            ;结束
CODE 	ENDS
		END  START