设在变量BUF为起始地址的字节存储单元中存放了5个有符号字节数，编写源程序找出其中最大和最小的数存放于MAX和MIN两个字节单元中。

DATA SEGMENT
    BUF DB 55H,66H,11H,44H,55H
    MAX DB ?
    MIN DB ?
DATA ENDS
CODE SEGMENT
    ASSUME DS:DATA,CS:CODE
START:MOV AX,DATA
      MOV DS,AX
      LEA SI,BUF
      MOV CX,5
      MOV BL,[SI]
      MOV AL,BL
      DEC CX
 NEXT:INC SI
      CMP AL,[SI]
      JGE A1
      MOV AL,[SI]
      JMP A2
   A1:CMP BL,[SI]
      JLE A2
      MOV BL,[SI]
   A2:LOOP NEXT
      MOV MAX,AL
      MOV MIN,BL
      MOV AH,4CH
      INT 21H
CODE ENDS
    END START