I'm not so sure about the Nova 1200. I think all the Novas had the RTC was on a standard I/O board, along with the serial interface, PTR, PTP. I remember two crystals, one 16.000 KHz for the clock. The other was for the Baud Rate generator, somewhere about 1 MHz. A minimal system had 3 cards (CPU, Memory, and I/O)
-John ============= > Talk about dusting of the old brain cells. > I seem to remember that the PDP 11/23s did indeed allow the use of the 60 > hz > as an interrupt for precision timing if that can actually be said. The > data > general nova 1200 also. Boy thats exposing ones age. > > On Sat, Dec 12, 2009 at 8:29 PM, Colby Gutierrez-Kraybill < > [email protected]> wrote: > >> >> I'm trying to get to the bottom of whether or not any computing >> equipment >> made around the advent of UNIX systems (or any time-slicing system) used >> the >> mains cycles of 60Hz as phase lock for the internal system clock. My >> guess >> is that perhaps they did not as the computing logic is DC based, but, I >> have >> memories of using an 68000 based UNIX system that I thought had its >> internal >> clock based off of the 60Hz mains... Not sure the vendor anymore. >> >> Thanks, Colby >> >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
