Re: I have a 15MHz IIgs!

[Michael J. Mahon <mjmahon@aol.com>]

Steven Hirsch <snhirsch@gmail.com> wrote:
> On 11/03/2012 04:45 PM, Steven Hirsch wrote:
> 
>> Very interesting.  When I hotrodded my ZIP GSX I installed Cypress CY7C199
>> 12nsec. 32kx8 parts for tag ram (changed sockets out for .3" width).  After
>> reading your comment, I swapped in a couple of UMC UM61256K-15s.  So far, so
>> good.  These have a script "m" in the model number - is that possibly what you
>> meant by "me" - or are some of these actually labeled with "me" (two letters)?
> 
> Almost forgot:  The data ram on my board is ZMD U62256ADC-07LL 70ns 32kx8
> .6" form factor.  I'm wondering if that's fast enough.
> 
> Are you saying you used the same exact part number for tag and data?  I
> wonder why the boards were equipped with different types for the two functions.
> 
> I'd have to do some further surgery to use .3" parts for the data ram. 
> It was hairy enough removing the original tag ram sockets, I'm not
> anxious to go through this again.
> 
> Steve

When I modified my ZipGS, I put in single-row sockets, so it will accept
either 0.3" or 0.6" SRAMs. 

Mine came with identical SRAMs. I suspect that when fast SRAMs were harder
to get (or more expensive) Zip used slower parts for the data, since access
time there is less critical. 

-michael - NadaNet 3.1 and AppleCrate II: http://home.comcast.net/~mjmahon