Re: Help with IIGS Memory

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

Shawn <smtrimbl@kuhub.cc.ukans.edu> wrote:

> Hello...
> I'm looking to fill my AE Rev D. GS-RAM Plus RAM Card (currently at 4MB
> out of possible 6MB) and my Apple Memory Card (currently at 256k out of
> 1MB).  Does anyone who's done this before have any tips on where to find
> the DRAMs these days? 
> 1) The GS-RAM Plus manual notes that it requires 1024k x 1 DRAM chips
> running at 12ns or less (the chips currently on my board are 10ns... I'm
> not sure if it would hurt to mix speeds...) with CAS before RAS refresh.

If the manual says that, it is wrong!  The required speed is 120 ns or
faster.

RAM rated at 100 ns or faster usually doesn't show the final zero, so
"HM511000-12" is 120 ns, for example.
 
> So my question here is, are these the only chips that will work ?

No.  You can generally use any brand you like, as long as they have the
right configuration (1024Kx1), support CAS before RAS refresh (all
current RAM should) and are 120 ns or faster.

> 3. Now as for the Apple Memory card... My card currently has Texas
> Instruments TMS4256-15NLA chips on it.  What other chips would work on
> it?  Anything I should stay away from?

Most chips labelled "4256" or "41256" can be used.  They are 256Kx1, 120
ns or faster, supporting CAS before RAS refresh.

(Some memory cards may work with 150 ns RAM, but I wouldn't recommend
it.)

-- 
David Empson
dempson@actrix.gen.nz
Snail Mail: P.O. Box 27-103, Wellington, New Zealand