Date : Mon, 10 May 2004 19:53:41 +0200 (BST)
From : Johan Heuseveldt <johan@...>
Subject: Re: 65c02
Hi Eelco,
> > > > gARetH baBB <hick.bbc@...> 04/27 4:31 >>>
> > > Has anyone come across a reference before about using a 65c02 in
> > > an Issue 7 BBC ?
On Fri 07 May, Eelco Huininga wrote:
> I've upgraded my model B issue 7 and as I recall there were some timing
> problems, pert iculary concerning the video controller. This was overcome
> by soldering two small capa citors on the mainboard. Yesterday I took a
> look inside the B. I'm using a Rockwell R65C02P2 and have soldered two
> 47pF ceramic capacitors accross legs 7 and 11 of IC29 and legs 7 and 11 of
> IC37. I 'm not sure if the 47p value is correct since the stamp has faded
> and is hardly readab le. If anyone needs to know the exact value, I could
> desolder them and plug them into my DVM to find out if the 47p value is
> correct. Just let me know.
I bought (not received yet) a 65c02 to do this experiment as well, so
your details are much appreciated.
If you can give the exact cap-values, I know what to dug out and solder
into the machine, in case the 6502/65c02 switch doesn't work from start.
> One other problem I've come accross is a timing problem with my Solidisk
> 32k+96k SWR u pgrade. It seems the 96k has a problem refreshing it's DRAM
> contents. The 32k board is working perfectly, so I guess Solidisk used
> DRAM's from different manufacturers. I ha ven't come accross a solution for
> this problem yet. Maybe one day I'll bring out the g ood 'ol oscilloscope
> and try to pinpoint the problem...
I'll have the same and need to do some resolder connections on all
wires, as these are very unreliable. Good to know about the possible
differences between the two banks of RAM.
> Hope this helps some of you guys...
This kind of exact information is always helpfull I reckon!
Thanks Eelco.
greetings,
Johan
--
Johan Heuseveldt <johan@... >
aka waarland
The best place is a Riscy place
One can always be kind to people about whom one cares nothing.