Re: IIc SD/MMC RAM

[dempson@actrix.gen.nz (David Empson)]

Roger Johnstone <roger@roger.geek.nz.removethisbit> wrote:

> In <1homysl.1akj9zoco0cx2N%dempson@actrix.gen.nz> David Empson wrote:
> > kaos116 <kaos116@comcast.net> wrote:
> > 
> >> Yes there is a memory expanision header inside. from what I have read
> >> and remember. All of the ][c's had it except the very first revisions.
> >> I think you could get up to 1 meg inside.
> > 
> > The memory expansion slot was added in the third generation of the IIc,
> > but the second generation (with UniDisk 3.5 support) had basically the
> > same logic board as the first generation (differed only in default ROM
> > size and serial port clocking).
> > 
> > The expansion slot is functionally equivalent to a RamWorks card in a
> > IIe: it has a single byte bank address which allows auxiliary memory
> > to be switched between up to 256 banks of 64KB, so the theoretical 
> > limit is 16 MB, but the hardware interface might not provide all of
> > the bits of the higher address bus.
> 
> David, I think your books have been stashed away for too long. The 
> original third-party memory cards for the IIc used bank switched memory,
> but Apple's memory card had a slinky interface just like the Apple II
> Memory Expansion Card used in the Apple II models with regular Apple Bus
> slots.

Oops, you're right. Sorry about that folks. I was getting confused with
the Applied Engineering product which plugged into the MMU socket.

Maybe I should think about getting rid of my books and stop posting here
if I'm starting to forget important details.

-- 
David Empson
dempson@actrix.gen.nz