[Coco] Memory expansion

[Joel Rees]

Timing can always be synthesized and adjusted. The question you should ask
is whether you need to put an independent refresh counter on the cart, and
how hard it would be.

2018年8月12日(日) 7:41 Bill Gunshannon <bill.gunshannon at hotmail.com>:

> Interesting.  So, how hard would it be to make one that took
>
> 4164's?  I was looking for some way to test memory chips and thought
>
> a Cart might be a good solution if expansion memory could be addressed
>
> from there.  When I said I could see a possible problem I was thinking
> about
>
> timing with the memory so far (electrically) from the CPU.
>
>
> Why would I want to do this, you ask?  I just spent about an hour pulling
>
> 4164 compatible chips out of old ISA PC memory expansion boards. With
>
> time, memory chips are going to get rarer.  Be nice to have a way to
> test them.
>
>
> bill
>
>
>
> On 08/11/2018 05:26 PM, Zippster wrote:
> > Yes, absolutely.  I have 512K of RAM on the CoCo PSG that can be banked
> in cart space.
> > With the proper logic, you can map it anywhere in memory, using /SLENB
> to suppress responses
> > from internal memory. There’s also the MOOH cart that others have
> mentioned.  So yes, it
> > can absolutely be done.
> >
> > - Ed
> >
> >
> >> On Aug 11, 2018, at 12:43 PM, Bill Gunshannon <
> bill.gunshannon at hotmail.com> wrote:
> >>
> >>
> >> A quick question for our hardware gurus.
> >>
> >>
> >> Would it be possible to make a cartridge memory expansion?
> >>
> >> That is a memory expansion on a cartridge that could be plugged
> >>
> >> into the MPI instead of inside the COCO itself.  I can think of
> >>
> >> some things that might be problematic but I am no expert by any
> >>
> >> stretch of the imagination.  So, I defer to the real experts.
> >>
> >>
> >> bill
> >>
> >>
> >>
> >> --
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> >
>
>
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