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The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

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;* GetKeyClock - Waits for keypress while updating time at specified location
;* on screen.
;*
;* Shows:   BIOS Interrupt - 16h, Functions 0 and 10h (Read Character)
;*                           16h, Functions 1 and 11h (Get Keyboard Status)
;*          DOS Functions - 2Ah (Get Date)
;*                          2Ch (Get Time)
;*
;* Uses:    vconfig - Video configuration structure (initialized
;*          by calling the GetVidConfig procedure)
;*
;* Params:  Row - Screen row for clock display
;*          Col - Screen column for clock display
;*
;* Return:  Short integer with key scan code in high byte and ASCII
;*          character code in low byte. Low byte is 0 for special
;*          keys (such as the "F" keys) which don't generate characters.
 
        .DATA
        PUBLIC  datestr
datestr BYTE    "  -  -     :  :  ", 0  ; Date/time string
        .CODE
 
GetKeyClock PROC,
        Row:WORD, Col:WORD
 
        LOCAL   service:BYTE
 
        INVOKE  GetShift                ; Check for extended keyboard
        mov     service, 11h            ; Assume Function 11h
        .IF     dx != 1                 ; If no extended keyboard:
        mov     service, 1              ; Use Function 1
        .ENDIF
 
        .WHILE  1
        mov     ah, service
        int     16h                     ; Get Keyboard Status
        .BREAK  .IF !zero?              ; If no key yet, update clock
 
; If not monochrome, color text, or black and white, skip clock update
; and poll keyboard again
 
        .CONTINUE .IF (vconfig.mode != 7) \
                   && (vconfig.mode != 3) \
                   && (vconfig.mode != 2)
 
; If 80-column text, get date and time from DOS before again
; polling keyboard, and display at upper right corner of screen.
 
        mov     ah, 2Ch                 ; Request time
        int     21h                     ; Get Time
        mov     dl, dh
        push    dx                      ; Save seconds,
        push    cx                      ;   minutes,
        mov     cl, ch                  ;   and
        push    cx                      ;   hours
        mov     ah, 2Ah                 ; Request date
        int     21h                     ; Get Date
        sub     cx, 1900                ; Subtract century, CL = year
        push    cx                      ; Save year,
        push    dx                      ;   day,
        mov     dl, dh                  ;   and
        push    dx                      ;   month
 
        mov     cx, 6
        sub     bx, bx
 
        .REPEAT
        pop     ax                      ; Recover all 6 numbers in AL
        aam                             ; Convert to unpacked BCD
        xchg    al, ah                  ; Switch bytes for word move
        or      ax, "00"                ; Make ASCII numerals
        mov     WORD PTR datestr[bx], ax; Copy to string
        add     bx, 3                   ;   at every third byte
        .UNTILCXZ
 
        INVOKE  StrWrite, Row, Col, ADDR datestr
        .ENDW                           ; Loop again for keypress
 
        mov     ah, service             ; 1 or 11h, depending on keybd
        dec     ah                      ; Set AH to 0 or 10h
        int     16h                     ; Get key to remove it from
        ret                             ;   keyboard buffer
 
GetKeyClock ENDP
                                    -♦-