Ever seen a Cromemco Cyclops in the wild?

William Sudbrink wh.sudbrink at verizon.net
Tue Jun 9 19:13:34 CDT 2020

No, I'm afraid not.  I can tell you from both personal experience and from the
designer (Terry Walker) that the chip is either a Mostek MK4008P-9 or an AMI
S4008-9.  I have used both chips.  See my web page:


Among other important features of those chips is the fact that the memory cells
are laid out in a 32 by 32 square and that the cells are multi-transistor per cell.
The multi-transistor design allows for non-destructive reads which is crucial for
the design.

Bill Sudbrink

-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Eric Smith via cctalk
Sent: Tuesday, June 09, 2020 7:40 PM
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Ever seen a Cromemco Cyclops in the wild?

On Tue, Jun 9, 2020 at 4:53 PM Boris Gimbarzevsky via cctalk <
cctalk at classiccmp.org> wrote:

> so probably read the Cyclops article, decided that $25 was way
> too much for one chip and never bothered.

In 1975 the B2102 or C2102 in the lidded ceramic package was more expensive
than the D2102 (CERDIP, frit seal, no die cavity lid), and far more
expensive than the P2102 (plastic). The B2102 or C2102 in low volume sold
for over $10 at the time, so $25 for one that had been manually de-lidded
then fit with a transparent lid doesn't seem like it was too unreasonable.

If you wanted to save a few bucks you could have bought a normal C2102 and
replaced the lid yourself.

Of course, the article didn't say that it was a 2102, but that was evident
from the pinout. The A/B/J/K jumpering was needed because the topology of
the 2102 and 2102A were different, which didn't matter in normal RAM

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