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MOV DS,AX MOV AL,DAT CMP AL,0 JZ ZERO JNS POSI MOV DL,’-’ DISPLAY

STOP: MOV AX,4C00H INT 21H

ZERO: MOV DL,’0’ DISPLAY JMP STOP

POSI: MOV DL,’+’ DISPLAY JMP STOP END START

4.23答： .MODEL SMALL .CODE

START: XOR BX,0 MOV CX,200 MOV DX,1

AGN: ADD BX,DX; 求和 INC DX INC DX LOOP AGN CALL BTOH MOV AX,4C00H INT 21H BTOH PROC MOV CL,4

MOV DL,BH;最高位 SHR DL,CL CMP DL,0AH JC N1 ADD DL,7

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N1: ADD DL,30H MOV AH,2 INT 21H

MOV DL,BH;次高位 AND DL,0FH CMP DL,0AH JC N2 ADD DL,7 N2: ADD DL,30H MOV AH,2 INT 21H

MOV DL,BL;次低位 SHR DL,CL CMP DL,0AH JC N3 ADD DL,7 N3: ADD DL,30H MOV AH,2 INT 21H

MOV DL,BL;最低位 AND DL,0FH CMP DL,0AH JC N4 ADD DL,7 N4: ADD DL,30H MOV AH,2 INT 21H RET

BTOH ENDP END START

4.24答：

.MODEL SMALL .DATA

DAT DB ……;准备100个数 RESULT DW ?

.CODE

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START: MOV AX,@DATA

MOV DS,AX MOV CX,99 LEA SI,DAT MOV DL,[SI] MOV DH,DL INC SI MOV BX,SI

AGN1: CMP DH,[SI];求出最大值

JNB NEXT1 MOV DH,[SI] NEXT1: INC SI

LOOP AGN1 MOV CX,99

AGN2: CMP DL,[BX];求出最小值

JB NEXT2 MOV DL,[BX] NEXT2: INC BX

LOOP AGN2 XOR AX,AX;求和 ADD DH,DL MOV AL,DH ADC AX,0 MOV RESULT,AX ;int 3 MOV AX,4C00H INT 21H END START 4.25答： DPLY0 MACRO MOV DL,30H MOV AH,2 INT 21H ENDM

DPLY1 MACRO MOV DL,31H

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MOV AH,2 INT 21H ENDM

.MODEL SMALL

.DATA

CNT DW 0AB3FH;准备数

.CODE

START: MOV AX,@DATA

MOV DS,AX MOV BX,CNT MOV CX,16 AGN: SHL BX,1 JC NEXT DPLY0 LOOP AGN NEXT: DPLY1 LOOP AGN MOV AX,4C00H INT 21H END START

4.26答：

.MODEL SMALL .DATA

STRG DB ……;准备字符串

.CODE

START: MOV AX,@DATA

MOV DS,AX LEA SI,STRG MOV CX,100 AGN: MOV AL,[SI] CMP AL,61H JB N1 CMP AL,7AH JA N1 SUB AL,20H N1: INC SI

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