Sure, this should do it:

Code:
settime:    ' Subroutine to write time to RTC
        RST = 1         ' Ready for transfer
        Shiftout IO, SCLK, LSBFIRST, [$8e, 0]  ' Enable write
        RST = 0         ' Reset RTC
        RST = 1         ' Ready for transfer
            ' Write all 8 RTC registers in burst mode
        Shiftout IO, SCLK, LSBFIRST, [$be, rtcsec, rtcmin, rtchr, rtcdate, rtcmonth, rtcday, rtcyear, 0]
        rst = 0        
        Return
steve