Re: Any non-memory cards for IIgs memory expansion slot?

[Dan Foster <usenet@evilphb.org>]

In article <qh4qni35fc.fsf@ruckus.brouhaha.com>, Eric Smith
<eric-no-spam-for-me@brouhaha.com> wrote:
> From the hardware reference, it doesn't look like the slot would be
> easily usable for anything but memory, but there were a lot of very
> creative people building peripherals.

I honestly don't see how one could use the mem exp slot on a GS for
anything other than memory accesses (whether RAM or ROM).

Comparing the pinouts on page 50 of the IIGS Hardware Reference manual
(mem exp slot) and page 173 (I/O exp slot)...

One can see that essentially, the mem exp slots only has pins to deal
with memory selection, refresh, transfer... whereas the I/O exp slots
has pins for DMA, IRQs, phase 0/1/2 clocks for synchronization, ready
assert, etc.

Probably other assumptions hardcoded such as in the slotmaker and Mega
II, and so forth... I'd love to be proven wrong, but I just don't see
how one could possibly make it do something other than mem stuff for the
mem exp slot.

-Dan