RE: Strange C128 & REU behavior
Date: 2004-02-09 16:49:36


On Mon, 9 Feb 2004, Baltissen, GJPAA (Ruud) wrote:
> I would say it is an hardware error but ....
> > I have tried two of my 128s and both my REUs with the same result.
> two 128s and two REUs with the same error ??? No, don't think so.

Exactly my thoughts too.

> Hmmm....., question: can reading a MMU-register also trigger an action?
> The MMU registers are situated at $FF00 and $D500 (IIRC). Question for
> Niklas: what is the starting address?

I've tried many different starting addresses, from $0000 to $E000 (which
should cause the C128 to wrap around after $FFFF, right?). Same result
everywhere. But I'm not sure that the REU sees the MMU registers at $FF00.
"Mapping the C128" is a little unclear on this, but I think that you can
make it see only RAM all the way. This is true for the shared RAM at the
bottom of memory anyway. When reading from RAM1 with a DMA device (VIC-II
and the REC), it doesn't see the shared RAM.

/Niklas Ramsberg
< .
    (:)  Bacon
< .

       Message was sent through the cbm-hackers mailing list

Archive generated by hypermail pre-2.1.8.