pc digital clock via parallel port using assembly language in tasm

maonin

maonin

@maonin-Qpfhlu Oct 22, 2024
hi, we have this project and we already have a code and the circuit but it is not working..
it's supposed to display the hours and minutes
the problems are:
1. the hour display is not displaying anything
2. the minute displays but it is advanced by one minute
please help us.


so here's the code:
TITLE CLOCK.ASM
DOSSEG
.MODEL SMALL
.STACK 0100H
.DATA
    PRINTERPORTBASEADDRESS equ 378h

.CODE
MAIN        PROC
    MOV AX, @DATA
    MOV DS, AX
    CALL RTIME    ; READ TIME
    CALL DisplayTime     ;DISPLAY TIME    
    
    MOV AX, 4C00H
    INT 21H
MAIN         ENDP
RTIME         PROC
    MOV AH, 02H
    INT 1AH
    RET
    ; CH - HOUR
    ; CL - MINUTES
    ; DH - SECONDS
RTIME        ENDP
DisplayTime PROC
    push     DX    ; was DH
    push     CX    ; was CL
;
    mov      AL,CH
    mov      DX,PRINTERPORTBASEADDRESS
    out        DX,AL
    mov      AL,01h
    mov      DX,PRINTERPORTBASEADDRESS+2
    out        DX,AL    ; enable display
    call       Delay
;
    mov      AL,00h
    mov      DX,PRINTERPORTBASEADDRESS+2
    out        DX,AL
    pop       AX    ; pop CL (minutes)
    mov      DX,PRINTERPORTBASEADDRESS
    out        DX,AL
    mov      AL,02h
    mov      DX,PRINTERPORTBASEADDRESS+2
    out        DX,AL    ; enable display
    call       Delay
;
    mov      AL,00h
    mov      DX,PRINTERPORTBASEADDRESS+2
    out        DX,AL
    pop       AX    ; pop DH (seconds)
    mov    AL,AH
    mov      DX,PRINTERPORTBASEADDRESS
    out        DX,AL
    mov      AL,08h
    mov      DX,PRINTERPORTBASEADDRESS+2
    out        DX,AL    ; enable display
    call       Delay
;
    mov      DX,PRINTERPORTBASEADDRESS+2
    mov      AL,00h
    out        DX,AL
    ret
DisplayTime ENDP
Delay Proc
        MOV CX, 00100h
    X:  PUSH CX
        MOV CX, 0FFFFh
    Y:  LOOP Y
        POP CX
        LOOP X
        RET
Delay ENDP
END
and the circuit:
#-Link-Snipped-#

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  • maonin

    maonin

    @maonin-Qpfhlu Oct 14, 2011

    please help. 😔