Subject: Re: [linuxsh-dev] Dreamcast RTC
To: Rene Malmgren <rene@dreamcastlinux.org>
From: M. R. Brown <marcusb@uwm.edu>
List: port-sh3
Date: 11/30/2000 18:34:51
The Dreamcast RTC is a 32-bit seconds counter at 0xa0710000 and 0xa0710004
(32-bit registers).  a0710000 contains the high 16-bits in its LSW and
a0710004 contains the low 16-bits.  The epoch or zero value (i.e. when the
RTC starts counting) is January 1, 1950 00:00.

I'm currently working on host-tools and I have a patch to newlib for
gettimeofday (simply adds 20 years to the RTC val to get the Unix epoch of
Jan. 1, 1970).  I'll post the code when I get to my workstation, tommorow.

Heh, Rene, we really should collaborate :).

M. R.

On Thu, 30 Nov 2000, Rene Malmgren wrote:

> Hi everyone
> 
> I have bean working on my own Linux port (well not so own) port for the
> DC. And I think I have managed to remove most of the problems. But one
> still alludes me. The DC doesn't use std RTC. Which means that the clock
> doesn't work out of the box. Does anyone know where one can get some
> information on the DC RTC. Preferably with some background information
> on how it works. Up to now I have managed to find some information
> written by Marcus (http://mc.pp.se/dc) on the Netbsd mailing list. So I
> have managed to Iron out some of the problems but there are still some
> left. I have also managed to get Dan's libdream to work (with some
> hacking) so I'll probably use his timer routines eventually.
> 
> /Rene
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