chp3_12b.asm

关于8086汇编的一些作业程序

stack segment stack'stack'
      dw 32 dup(?)
stack ends
data segment
W DD 9487FE26H
W1 DD ?
data ends
code segment
begin proc far
      assume ss:stack,cs:code,ds:data
      push ds
      sub ax,ax
      push ax
      mov ax,data
      mov ds,ax
      MOV AX,WORD PTR W+2
      CMP AX,0
      JL ANEG
      MOV WORD PTR W1+2,AX
      MOV BX,WORD PTR W
      MOV WORD PTR W1,BX
      JMP EXIT
ANEG: MOV BX,WORD PTR W
      NEG BX
      NOT AX
      XOR AX,8000H
      MOV WORD PTR W1,BX
      MOV WORD PTR W1+2,AX      
     
EXIT:
      ret
begin endp
code ends
     end begin