Re: Chips & Processors & Oscillators and other Go Fast Goodies?

[Rubywand <rubywand@swbell.net>]

Marvin Miller writes ...
> 
> Hi Folks;
> 
> My ZipGs arrived today as did my Applied Engineering Memory card. They
> look great and came with manuals and everything! (thanks Greg B.!!)
> 
> Some questions;
> 
 ....

> Also, I'd like to upgrade both the cache and the oscillator on the
> ZipGs. The oscillator just pulls in & out and has 4 little feet on
> each corner. I understand that there is some issues as to whether you
> have narrow or wide cache chips- mine are pretty wide and there's only
> two, although there are two empty sockets next to it. I suspect the
> 64k chips go there. Where to get these great items?
> 

     The main issue with the wider RAM IC's is that they are harder to find.
Below is some info on wide and skinny RAMs you might use from the newsgroup
FAQs.


Csa2 FAQs-on-Ground ref: Csa2ACCEL.txt

>>
024- What kind of RAMs do I need for a TWGS or ZipGS speedup? 

     You need fast 32k x 8 Static RAM in a 28-pin Dip package. If your RAM
sockets are "skinny" (about as fat as a typical 74xx TTL IC), you want a
300-mil wide package. Otherwise, you will need a 600-mil wide IC or a socket
adaptor for 300-mil (or do the socket mods described earlier in this FAQ). 

     Fast 600-mil package 32k x 8 SRAMs are fairly rare. However, the
IDT71256 is supposed to be available at good speeds (25ns-40ns) in a 600-mil
version from Integrated Device Technology. 

     The selection of 300-mil 32k x 8 SRAMs is much larger: Cypress's
CY7C199, Hitachi's HM62256, ... . 
<<

     Places to look would be Digi-Key, Newark, Mouser, and local outlets for
distributors like Wyle ( http://www.wyle.com/ ) and Insight (
http://www.insight-electronics.com/order/ ).



     The mod to allow using the skinny RAMs is fairly easy. It's described in
the FAQs at ...

http://home.swbell.net/rubywand/Csa2ACCEL.html#016 .




Rubywand