7a8
;******************************************        
;*    Routine to send a DAYTIME command   *
;*    to your TNC with the setting of     *
;*    the real time clock in your PC      *
;******************************************

        
        jmp start

outstr: db  'DAYTIME '
val:    db  10 dup 0,0D            ;Space for year,month,day,time and a CR
length equ $-outstr        
        


start:
        mov ah,04H              ; Read real time clock date
        int 1aH

        mov bp,val
        
        mov bl,cl                ;Year
        call calc
        mov bl,dh                ;Month
        call calc
        mov bl,dl                ;Day
        call calc

        mov ah,02H              ;Read real time clock time
        int 1aH

        mov bl,ch
        call calc
        mov bl,cl
        call calc

        jmp output


calc:
        mov al,bl
        shr al,4                  ;We want the high nibble...
        and al,0f
        add al,030
        mov b[bp],al            ;first character in year
        inc bp

        mov al,bl
        and al,0f
        add al,030
        mov b[bp],al            ;second character in year
        inc bp

        ret

        
output:

        mov bp,outstr            ;Pointer to the daytime string
        mov si,0
        mov dx,02e8H             ;COM4 port address
        mov cx,19                ;19 characters to output

loopi:
        mov al,b[bp+si]
        out dx,al                ;output character to COM4 port
                                 
        inc si                   ;and advance SI

        push dx
flush:
        mov dx,02ed
        in al,dx
        test al,32              ;wait for output buffer to be empty
        jz flush

        pop dx
        
        loop loopi               ;next character
        
        
        mov ax,04c00            ;That's it!
        int 21H

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