统计一串字节型的有符号数的最大值、最小值，正、负数个数，为什么这段程序运行不了？

DATA SEGMENT
BUF DB 12,-9,56,-5,-89,18,-41,22,45,99
NUM DB ?;存放正数个数
NUM1 DB ?;存放负数个数
MAX DW ?;存放最大值
MIN DW ?;存放最小值
DATA ENDS
CODE SEGMENT
ASSUME CS:CODE,DS:DATA
START:MOV AX,DATA
MOV DS,AX
MOV BX,OFFSET BUF
LEA SI,BUF
MOV BP,[SI]
MOV SP,[SI]
MOV CX,10
L1: CMP BYTE PTR [BX],0
JGE L2
INC AL
L2: INC BX
LOOP L1
MOV NUM,AL
MOV AX,4CH
INT 21H
L3: CMP BYTE PTR [BX],0
JGE L4
INC AH
L4: INC BX
LOOP L3
MOV NUM1,AH
MOV AX,4CH
INT 21H
L5: DEC CX
JZ LAST
ADD SI,4
MOV DI,[SI]
CMP BP,DI
JGE L6
MOV BP,DI
L6: CMP SP,DI
JNG L5
MOV SP,DI
JMP L5
LAST: MOV MAX,BP
MOV MIN,SP
MOV AX,4CH
INT 21H
CODE ENDS
END START

https://blog.csdn.net/sunweixiang1002/article/details/53048080