B_P     EQU BYTE PTR
W_P     EQU WORD PTR
D_P     EQU DWORD PTR
CODE    SEGMENT
ASSUME  CS:CODE,DS:CODEORG 100H
;主程序开始
NEWSTAR:JMP STAREVEN
NUM1    DW 0,0
NUM2    DW 0,0
NUM3    DW 0,0
JGV4    DW 0,0
YSF     LABEL WORD
YSF1    DB 0
YSF2    DB 0
JUV     DB 0
UV      DB 0
;使DS:SI指向第一有效字符
OVERS   LABEL NEARCLDPUSH AX
OVERS1:LODSBCMP AL,' 'JZ OVERS1CMP AL,9JZ OVERS1DEC SICMP AL,13POP AXRET
;输出一个制表符
TAB     LABEL NEARMOV AL,9JMP SHORT DISP
;输出一个回车换行符
CRLF    LABEL NEARMOV AL,13CALL DISPMOV AL,10
;显示一个字符
DISP    LABEL NEARPUSH AXPUSH DXMOV AH,2MOV DL,ALINT 21HPOP DXPOP AXRET
;检查是否为运算符
ISYSF   LABEL NEARCLDLODSBCALL ISJJJZ ISYSF1CALL ISIIJZ ISYSF1DEC SI
ISYSF1:RET
;检查是否是加减运算
ISJJ    LABEL NEARCMP AL,'+'JZ ISYSF1CMP AL,'-'RET
;检查是否为乘除运算
ISII    LABEL NEARCMP AL,'*'JZ ISYSF1CMP AL,'/'JZ ISYSF1CMP AL,'\'RET
;数据输出
;CX=10 十进制
;CX=16 十六进制
DOUT    LABEL NEARPUSH AXPUSH BXPUSH DXPUSH BPXOR BP,BP
DOUT1:INC BPPUSH AXMOV AX,DXXOR DX,DXDIV CXMOV BX,AXPOP AXDIV CXPUSH DXMOV DX,BXOR BX,AXJNZ DOUT1
DOUT2:POP AXADD AL,'0'CMP AL,'9'JBE DOUT3ADD AL,'A'-'9'-1
DOUT3:CALL DISPDEC BPJNZ DOUT2POP BPPOP DXPOP BXPOP AXRET
;输入数据在DX:AX中返回
;CX=0 数据为10进制
;CX#0 数据为16进制
DATE    LABEL NEARPUSH BXPUSH BPPUSH DIXOR AX,AXXOR DX,DX
DATE1:MOV DI,AXLODSBCMP AL,'0'JB DATE7CMP AL,'9'JA DATE6
DATE2:AND AX,0FHSHL DI,1RCL DX,1MOV BX,DIMOV BP,DXSHL DI,1RCL DX,1SHL DI,1RCL DX,1JCXZ DATE3SHL DI,1RCL DX,1Jmp short DATE4
DATE3:ADD DI,BXADC DX,BP
DATE4:ADD AX,DIADC DX,0JMP DATE1
DATE5:ADD AL,9JMP DATE2
DATE6:JCXZ DATE7CMP AL,'A'JB DATE7CMP AL,'F'JBE DATE5CMP AL,'a'JB DATE7CMP AL,'f'JBE DATE5
DATE7:MOV AX,DIDEC SIOR DI,DXPOP DIPOP BPPOP BXRET
;数据1与数据2根据YSF1进行加减运算
JSJJ    LABEL NEARMOV AX,NUM2MOV DX,NUM2+2CMP YSF1,'+'JZ JSJJ1SUB NUM1,AXSBB NUM1+2,DXJMP SHORT JSJJ2
JSJJ1:ADD NUM1,AXADC NUM1+2,DX
JSJJ2:RET
;数据1与数据2根据YSF1进行乘除运算
JSII1   LABEL NEARMOV BX,OFFSET NUM1JMP SHORT JSII2_1
;数据2与数据3根据YSF2进行乘除运算
JSII2   LABEL NEARMOV BX,OFFSET NUM2
JSII2_1:DB 66HMOV AX,[BX]DB 66HMOV CX,[BX+4]CMP YSF2,'*'JNZ JSII2_2DB 66HIMUL CXJMP SHORT JSII2_3
JSII2_2:DB 66HCWDDB 66HIDIV CXCMP YSF2,'/'JZ JSII2_3DB 66HXCHG DX,AX
JSII2_3:DB 66HMOV [BX],AXRET
;显示结果
XUJG    LABEL NEARMOV AX,JGV4MOV DX,JGV4+2MOV CX,10CMP UV,10JZ XUJG0MOV CX,16
XUJG0:TEST DX,8000HJZ XUJG1CMP UV,10JZ XUJG2CALL DOUT
XUJG2:NOT AXNOT DXADD AX,1ADC DX,0PUSH AXCMP UV,10JZ XUJG3MOV AL,' 'CALL DISPMOV AL,'('CALL DISP
XUJG3:MOV AL,'-'CALL DISPPOP AXCMP UV,10JZ XUJG1CALL DOUTMOV AL,')'CALL DISPRET
XUJG1:CALL DOUTRET
;计算结果放入DX:AX中
JSJG    LABEL NEARCALL JSJJMOV AX,NUM1MOV DX,NUM1+2RET
;从DS:SI处取一个数据
LOADATE LABEL NEARLODSBCMP AL,'('JZ LOADATE1DEC SIPUSH CXXOR CX,CXCMP UV,10JZ LOADATE0INC CX          ;取16进制数
LOADATE0:CALL DATE       ;取数据放入DX:AX中POP CXRET
LOADATE1:PUSH NUM1       ;保存数据1数据2及运算符PUSH NUM1+2PUSH NUM2PUSH NUM2+2PUSH YSFINC JUVMOV JGV4,0      ;结果值清零MOV JGV4+2,0
;进行四则运算
SZYS    LABEL NEARCALL ISYSF      ;首字符是运算符？JZ SZYS2CALL LOADATE    ;不是，取数并保存MOV NUM1,AXMOV NUM1+2,DX
SZYS1:XOR AX,AX       ;数据2清零MOV NUM2,AXMOV NUM2+2,AXCALL ISYSF      ;下个是运算符？JZ SZYS3JNZ SZYS6
SZYS2:PUSH AXMOV AX,JGV4     ;将结果作为数据1MOV NUM1,AXMOV AX,JGV4+2MOV NUM1+2,AXPOP AX
SZYS3:MOV YSF1,ALMOV YSF2,ALCALL ISJJ       ;是加减运算转JZ SZYS4CALL LOADATE    ;取数据2MOV NUM2,AXMOV NUM2+2,DXCALL JSII1      ;数据1与数据2根据YSF1进行乘除运算JMP SZYS1       ;    结果保存在数据1中
SZYS4:CALL LOADATE    ;取数据2并保存MOV NUM2,AXMOV NUM2+2,DX
SZYS4_1:CALL ISYSFJNZ SZYS6CALL ISJJ       ;运算符2是加减运算？JNZ SZYS5       ;不是转PUSH AXCALL JSJJ       ;数据1与数据2根据YSF1进行加减运算POP AX          ;    结果保存在数据1中MOV YSF1,AL     ;保存新的运算符JMP SZYS4
SZYS5:MOV YSF2,AL     ;保存运算符2CALL LOADATE    ;取数据3MOV NUM3,AXMOV NUM3+2,DXCALL JSII2      ;数据2与数据3根据YSF2进行乘除运算JMP SZYS4_1     ;    结果保存在数据2中
SZYS6:MOV CL,ALCMP AL,13JNZ SZYS9
SZYS7:CALL JSJGCMP JUV,0JZ SZYS8DEC JUVPOP YSFPOP NUM2+2POP NUM2POP NUM1+2POP NUM1RET
SZYS8:CMP CL,')'JZ SZYS10MOV JGV4,AXMOV JGV4+2,DXJNZ SZYS12
SZYS9:CMP AL,')'JNZ SZYS11INC SIJMP SZYS7
SZYS10:MOV NUM1,AXMOV NUM1+2,DXJMP SZYS1
SZYS11:STCRET
SZYS12:CLCRET
;数制处理
UVIL    LABEL NEARPUSH SI
UVIL1:LODSBCMP AL,' 'JZ UVIL2CMP AL,9JZ UVIL2CMP AL,13JZ UVIL4JNZ UVIL1
UVIL2:MOV BX,SICALL OVERSJZ UVIL3LODSWCALL OVERSPOP SIJNZ SZYS11CMP AX,'01'JNZ SZYS11PUSH SIMOV UV,10
UVIL3:MOV AL,13MOV [BX-1],AL
UVIL4:POP SICLCRET
;预置结果
YVJG    LABEL NEARMOV AH,52HINT 21HMOV AX,ES:[BX-2]MOV DS,AXMOV AX,DS:[0CH]MOV CS:JGV4,AXMOV AX,DS:[0EH]MOV CS:JGV4+2,AXPUSH CSPOP DSPUSH CSPOP ESRET
;保存结果
BCJG    LABEL NEARMOV AH,52HINT 21HMOV AX,ES:[BX-2]MOV DS,AXMOV AX,CS:JGV4MOV DS:[0CH],AXMOV AX,CS:JGV4+2MOV DS:[0EH],AXPUSH CSPOP DSPUSH CSPOP ESRET
STAR:MOV SI,81HCLDCALL OVERSJNZ STAR1
STAR0:MOV DX,OFFSET MESS1JMP STAR4
STAR1:CALL YVJGCALL UVILJB STAR0MOV SAVESP,SPCALL SZYSMOV SP,SAVESPMOV DX,OFFSET MESS2JB STAR4CALL CRLFCALL XUJGCALL BCJGMOV DX,OFFSET MESS3
STAR4:MOV AH,9INT 21HINT 20H
SAVESP  DW 0
MESS1   DB 13,10,'  Syntax:',13,10DB '     JS  <Expression>  [10]',13,10,'$'
MESS2   DB 'Error in expression !$'
MESS3   DB 13,10,'$'
CODE    ENDSEND NEWSTAR