关于汇编的推箱子程游戏计时功能的实现，改了半天还是不行？什么原因？

小弟遇到一个问题，这是网上一个汇编写成的推箱子游戏，但是里面却不能实现计时和显示时间的功能，里面有这部分代码，但是小弟水平有限，不会弄，求大神帮帮小弟
;******************************************************
;时间数据段      
;******************************************************
TDATA_SEG     SEGMENT   PARA
;=======================================================================================
count DW        0   
sec   DW        0
min   DW        0
hours DW        0                        
;=======================================================================================
TDATA_SEG     ENDS
;------------------------------------------------------------------------------------------
;----------------------------------------------------------------------------
Gametime      PROC      NEAR    ;游戏时间
              MOV       DX,SEG tdata_seg
              MOV       DS,DX                                                                 
              MOV       AL,1ch
              MOV       AH,35h
              INT       21h
              PUSH      DX
              PUSH      DS
              MOV       AX,SEG CLInt
              MOV       DS,AX
              LEA       DX,CLInt
              MOV       AL,1ch
              MOV       AH,25h
              INT       21h
              IN        AL,21h
              AND       AL,0feh
              OUT       21h,AL
              STI
              POP       DS              
              POP       DX
              CALL      systime
              CALL      StartGame
              
              MOV       AL,1ch
              MOV       AH,25h
              INT       21h              
              RET
gametime      ENDP
;---------------------------------------------------------------------
CLInt         PROC      NEAR
              PUSH      DS
              PUSH      BX
              MOV       BX,SEG count
              MOV       DS,BX
              LEA       BX,count
              INC       BX
             CMP        BX,18
              JNE       exit6
              CALL      INCtest
exit6:        MOV       AL,20h
              OUT       20h,AL
              POP       BX
              POP       DS
             RET
CLInt         ENDP
;---------------------------------------------------------
INCtest       PROC      NEAR
              MOV       AH,2
              MOV       DH,20
              MOV       DL,25
              INT       10h
              MOV       BX,0
              ADD       BX,2
              INC       BX
              CMP       BX,60
              JNE       RETurn
              CALL      INCtest
RETurn:      
              setpos    16,54
              MOV       AH,02h
              MOV       BX, hours
              CALL      convert
              MOV       AH,02h
              MOV       DL,3ah
              INT       21h
              MOV       AH,02h
              MOV       BX,min
              CALL      convert
              MOV       AH,02h
              MOV       DL,3ah
              INT       21h
              MOV       AH,02h
              MOV       BX,sec
              CALL      convert
              RET
INCtest       ENDP
;----------------------------------------------------------              
convert       PROC      NEAR
              MOV       CX,10d
              MOV       AX,BX
              MOV       DX,0
              DIV       CX
             MOV       BX,DX
              
              MOV       DL,AL      
              ADD       DL,30h
              MOV       AH,02h
              INT       21h
              MOV       DL,BL
              ADD       DL,30h
             MOV       AH,02h
              INT       21h
              RET
convert       ENDP                           
;--------------------------------------------------------------


[ 本帖最后由 yle 于 2012-5-31 20:14 编辑 ]