[Coco] Memory expansion

[Bill Gunshannon]

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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>