怎么样才能使以下程序实现P键暂停呢？新手求帮，大神们在哪？只是部分程序，还请体谅

Question

SELECTSPEED:
;显示提示信息
MOV AH,09H
MOV DX,OFFSET STARTMSG1
INT 21H
MOV DX,OFFSET STARTMSG2
INT 21H
MOV DX,OFFSET STARTMSG3
INT 21H
MOV DX,OFFSET STARTMSG4
INT 21H
MOV DX,OFFSET STARTMSG5
INT 21H
;检测CTRL+BREAK 或ＣＴＲＬ＋Ｃ
MOV AH,08H
INT 21H
SUB AL,'0'
MOV CL,AL
AND AL,3
CMP AL,CL
JNE SELECTSPEED
INC AL
INC CL
MUL CL

MOV SPEED, AL

;SET    GRAPHICS：640*480*16色　
MOV AH,00H
MOV AL,12H
INT 10H
;设置调色板: BH 调色板ID, BL 和ID使用的颜色
MOV AH,0BH
MOV BH,01
MOV BL,00H
INT 10H

;START  GAME
CALL    INITGAME
CALL    BEGIN
CALL    DELAY
MOV     TIM,    0H

LOOP1:
STI
MOV AL,TIM
CMP AL,SPEED
JG TIME
MOV AH,1
INT 16H
JZ LOOP1
MOV AH,0
INT 16H
CMP AL,1BH
JZ EXIT
CMP AL,'a'
JZ KA
CMP AL,'w'
JZ KS
CMP AL,'d'
JZ KD
CMP AL,'s'
JNZ TIME
CMP AL,'P '；自己加的
JZ STOP；自己加的
STOP: MOV AH,00H；自己加的
INT 16H； 自己加的