Re: GS memory expansion

[Rubywand <rubywand@swbell.net>]

Jim Thompson writes ...
> 
> Since 41256 chips don't all say "41256", is there a good resource that will
> tell you which manufacturer's chip is a 41256? Or is there a particular
> number pattern that exists? I'd prefer not to have to buy new chips from
> Jameco when I'm sure that I've got loads of these chips sitting on old PCXT
> mem cards or motherboards.
>

     One point of possible confusion is that some 32k x 8 SRAMs also
have the "41256" type number. However the SRAMs have more pins
(typically 28). If you were to come across a 28-pin RAM IC marked
PDM41256SA-10, you would have a 32k x 8 SRAM rated at 10ns speed.

     The 256k x 1 DRAMs normally have 16 pins. Also, as you observe, not
all 256k x 1 DRAMs have the 41256 number. The Sharp LH21256-10 is a 256k
x 1 16-pin DRAM rated at 100ns.


     Besides the place mentioned by Greg, a good place to look up IC's
is ...
http://www.blee.net/chipdir/chipdir.htm 

 
> Also, did Apple only make 1 or 2 meg cards? Is there a way to tell which
> card is which?

     If you are talking about IIgs boards for the Mem Expansion Slot,
Apple made the 1MB board. As far as I know, they did not make any other
boards for the IIgs Mem Expansion Slot.




Rubywand