I think the basic number you're looking for is "2101" from the same 1K
series as the famous "2102" which is a 16-pin 1kx1 with separate in and out.
The 2101's I have are not fast enough to meet the 200ns spec. However, not
much of anything that was readily available at the time the PET model 2001
came out was that fast. Either it was quite a bit faster, e.g. 2147, 2115,
etc, or it was slower, e.g. 2114, 21L02, TMS4044 etc, which were typically
450 ns at that point in time. Those 450 ns parts worked handsomely with the
1 MHz 6502. Perhaps you'd be able to use a 2101.
Let me know if you think that might work for you. I've had my small supply
(maybe 4 pieces) since back in '76-'77 when I got my original 6501, though
I've never used them for anything.
Dick
-----Original Message-----
From: Pete Turnbull <pete_at_dunnington.u-net.com>
To: classiccmp_at_classiccmp.org <classiccmp_at_classiccmp.org>
Date: Tuesday, March 21, 2000 2:39 AM
Subject: Re: Mos Technology RAM wanted
>On Mar 20, 13:23, John Honniball wrote:
>>
>> On Sun, 19 Mar 2000 21:28:09 GMT Pete Turnbull
><pete_at_dunnington.u-net.com> wrote:
>
>> > One of the MCS6550 RAMs has gone west. Does anyone have a spare, or an
>> > equivalent, for sale? It's a 22-pin 1024 x 4 200ns static RAM.
>>
>> I'll have to check the RAMs in the spare PET that I
>> keep in the garage. Can't remember whether they're SRAMs
>> or DRAMs in the bigger PETs.
>
>Only the oldest 2001-x PETs use those SRAMs. I guess it's time to build
>that upgrade board (a PAL, a pair of EPROMS, and some 6264s, a 62256, or
>some cast-off PC cache).
>
>--
>
>Pete Peter Turnbull
> Dept. of Computer Science
> University of York
Received on Tue Mar 21 2000 - 09:51:28 GMT