[comp.sys.amiga] system clock

sjm@sun.acs.udel.edu (Steve Morris) (11/09/89)

In article <32315@auc.UUCP> rar@auc.UUCP (Rodney Ricks) writes:
>
>Oh, and for those whose complain about real-time clock inaccuracies,...

I have not had any problems with the real time clock in my A500, but
if I leave the machine on for extended periods of time I find that
the Amiga DOS clock seems to lose ~5 min / day. Anyone else notice this?

  -Steven

mlelstv@immd4.informatik.uni-erlangen.de (Michael van Elst ) (11/20/89)

sjm@sun.acs.udel.edu (Steve Morris) writes:

>I have not had any problems with the real time clock in my A500, but
>if I leave the machine on for extended periods of time I find that
>the Amiga DOS clock seems to lose ~5 min / day. Anyone else notice this?

The system clock is not very accurate (at least on an A500).

The A500 timer is clocked from the video frequency (VBLANK signal) since
the power supply does not generate a 50Hz (or 60Hz) signal. Maybe they
(Commodore) changed the power supply with later A500s.
Nevertheless, you can feed in a separate clock signal to get it more
accurate.

The battery-backed up clock is not influenced by the problem listed above.
Yet, it is only used when initializing the system clock with the
SetClock command.

				Michael van Elst

E-mail: UUCP: ...uunet!unido!fauern!immd4!mlelstv