Re: CBM-II solderless memory expansion

On 04/12/2018 10:05 PM, Michał Pleban wrote:
> Hello!
> 
> The widely known method of expanding a CBM-II memory requires soldering
> several things on the motherboard, which is doable but not for the faint
> of the heart.
> 
> Alternatively you can also use the expansion port to connect a big SRAM
> chip which could expand the memory for the 6509, but it would not be
> seen by the 8088 card.
> 
> So I thought about an easier way to expand the memory. The standard
> method uses 41256 chips instead of 4164. But how about using 4464
> instead of 4164? The memory banks would still be 64kB in size, which
> means that all that is needed is a custom PLA; PLA is socketed on most
> motherboards so it could be a straightforward expansion.
> 
> Just to test the waters, I replaced a row of 4164's today with two
> 4464's and it works fine. Did anybody go down this route before?

A 4464 cannot be put in place of a 4164, so I don't quite see how to 
make that 'solderless'... Could you provide a bit more detail?

  Gerit