C8279 EQU 20AH
       D8279 EQU 208H
       C8255 EQU 203H
       P8255C EQU 202H
CODE SEGMENT
  ASSUME CS:CODE,DS:CODE
  START:PUSH CS
        POP DS
    INI:MOV DX,C8255
        MOV AL,80H
        OUT DX,AL
        MOV DX,C8279
        MOV AL,00H
        OUT DX,AL
        MOV AL,2AH
        OUT DX,AL
	MOV AL,90H
	OUT DX,AL
        MOV AL,0D1H
        OUT DX,AL
	JMP SHORT $+2
  WAIT1:IN AL,DX
        MOV AH,AL
        AND AL,80H
        JNZ WAIT1
        MOV AL,AH
        AND AL,0FH
        CMP AL,00H
        JE WAIT1
        LEA BX,STEP
    RUN:CALL CHKKEY
        CALL DISPLAY
        MOV CX,08H
  LOOP3:MOV DX,P8255C
        MOV AL,[SI]
        OUT DX,AL
        INC SI
        CALL DELAY
        LOOP LOOP3
        JMP RUN
CHKKEY PROC NEAR
  RDKEY:MOV DX,C8279
        IN AL,DX
        MOV AH,AL
        AND AL,80H
        CMP AL,80H
        JE RDKEY
        MOV AL,AH
        AND AL,0FH
        CMP AL,00H
        JE RTN
        MOV AL,40H
        OUT DX,AL
        MOV DX,D8279
        IN AL,DX
    CHK:CMP AL,15H
        JE QUIT
        CMP AL,0AH
        JNC DIRE
        MOV DELAYTIME,AL
        JMP RTN
   DIRE:CMP AL,12H
        JNE NEXT
        MOV DIRDSP,40H
        LEA BX,STEP
        JMP RTN
   NEXT:CMP AL,13H
        JNE RTN
        MOV DIRDSP,46H
        LEA BX,STEP
        ADD BX,07H
    RTN:MOV SI,BX
        RET
CHKKEY ENDP
DELAY PROC NEAR
        PUSH CX
        MOV CX,0AH
        SUB CL,DELAYTIME
  LOOP1:PUSH CX
        MOV CX,03FFH
  LOOP2:NOP
        LOOP LOOP2
        POP CX
        LOOP LOOP1
        POP CX
        RET
DELAY ENDP
DISPLAY PROC NEAR
        PUSH BX
        MOV DX,D8279
        MOV AL,DELAYTIME
        LEA BX,LED
        XLAT
        OUT DX,AL
        MOV AL,DIRDSP
        OUT DX,AL
        MOV CX,0006H
        LEA BX,DSP
  LOOP4:MOV AL,[BX]
        OUT DX,AL
        INC BX
        LOOP LOOP4
        MOV DX,C8279
        MOV AL,0C2H
        OUT DX,AL
        POP BX
        RET
DISPLAY ENDP
   QUIT:MOV DX,C8279
        MOV AL,0D2H
        OUT DX,AL
        jmp $
   LED DB 3FH,06H,5BH,4FH,66H
       DB 6DH,7DH,07H,7FH,6FH
   DSP DB 5EH,79H,79H,73H,6DH,0EDH
   DELAYTIME DB 01H
   STEP DB 04H,05H,01H,09H,08H
        DB 0AH,02H,06H,02H,0AH
        DB 08H,09H,01H,05H,04H
   DIRDSP DB 40H
CODE ENDS
END START