Re: RAMWorks 2 Chips

[mdj <mdj.mdj@gmail.com>]

On Jun 14, 1:06 pm, demp...@actrix.gen.nz (David Empson) wrote:

> It looks like it may have been written originally to claim 16 MB maximum
> capacity, but then amended to reflect the actual maximum they were
> planning on selling, but someone missed changing the "16" to "3".

I believe that > 3mb capacities were in fact sold made to order, by
piggybacking additional 2mb expanders on top of the existing one.
While I've not ever seen such a thing myself, it seems that by re-
exporting the piggybacks physical interface you could support as many
as you needed, and simply supply a different PAL for each board so
that it selected the correct bank based on the high order nibble of
the bank select register. Since all expanders would have the same
memory configuration, you could probably get away with only generating
refresh on the first card and have the others piggyback off it.

I'm somewhat surprised that nobody has bothered to re manufacture a
higher capacity version of the expander. There are times when having 4
(or 5) mb on the IIe would be rather handy.

Matt