9 Jun
2020
9 Jun
'20
3:53 p.m.
Funny how wetware memory works. I have that issue of Popular
Electronics somewhere in my collection and would have seen the
article as I would read it cover to cover after it arrived in mail.
While looking at the issue again, remembered reading next article on
PLL's so probably read the Cyclops article, decided that $25 was way
too much for one chip and never bothered. However, I do have a lot
of old RAM chips so might give it a try some day. What I do recall
about that era that a 1024 bit SRAM cost about $10 in Canada. (That
was in days when we made a profit selling beer for $0.25 at TGIF).
Boris Gimbarzevsky
I think a Stanford AI lab has one in a display case.
Any others out there?
It was supposedly "commercial" but I don't even remember ever seeing
an ad for the Cyclops from Cromemco and I had a really good stash of
Cromemco literature and hardware.
I do remember the BYTE article where you pop the top off of a DRAM
chip to make a Camera but that was 1983-ish, nearly a decade after
the Cromemco Cyclops was supposedly "commercial". In the discussions
I had in the 80's none of us seemed to know about the Cromemco
Cyclops having preceded it.
Tim N3QE
9 Jun
9 Jun
4:40 p.m.
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
applications.
5:13 p.m.
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:
http://wsudbrink.dyndns.org:8080/cyclops/index.html
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
applications.
--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
10 Jun
10 Jun
9:37 a.m.
On Tue, Jun 9, 2020 at 6:14 PM William Sudbrink <wh.sudbrink at verizon.net>
wrote:
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:
http://wsudbrink.dyndns.org:8080/cyclops/index.html
You obviously must be correct, and use of a DRAM makes much more sense than
an SRAM. It's possible that an SRAM could be made to work as an image
sensor, but it would not be anywhere near as sensitive as a DRAM. When,
back in 1975, I compared the pinout to the data books I had on hand, and
observed that it exactly matched the 2102, and didn't search any further. I
had no idea that the MK4006 and MK4008 dynamic RAMs happen to have the same
pinout as the 2102 static RAM. Intel's own 1K DRAMs (1103 PMOS, 2105 NMOS)
do not share that pinout.
9:49 a.m.
The really interesting thing (to me anyway) is just how
it works. The cells are 3T1C (3 transistor, 1 capacitor).
There?s a good diagram here:
https://electronics.stackexchange.com/questions/477173/the-detailed-working…
I assumed that the photons were just allowing charge to
escape across the capacitor. Terry corrected me. The
transistor labeled ?T2? in the above diagram is what is
light sensitive. When struck by photons, T2 allows charge
to leak to ground, discharging the cap and ?flipping? the
bit to zero.
Bill
From: Eric Smith [mailto:spacewar at gmail.com]
Sent: Wednesday, June 10, 2020 12:38 PM
To: William Sudbrink; General Discussion: On-Topic and Off-Topic Posts
Subject: Re: Ever seen a Cromemco Cyclops in the wild?
On Tue, Jun 9, 2020 at 6:14 PM William Sudbrink <wh.sudbrink at verizon.net> wrote:
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:
http://wsudbrink.dyndns.org:8080/cyclops/index.html
You obviously must be correct, and use of a DRAM makes much more sense than an SRAM.
It's possible that an SRAM could be made to work as an image sensor, but it would not
be anywhere near as sensitive as a DRAM. When, back in 1975, I compared the pinout to the
data books I had on hand, and observed that it exactly matched the 2102, and didn't
search any further. I had no idea that the MK4006 and MK4008 dynamic RAMs happen to have
the same pinout as the 2102 static RAM. Intel's own 1K DRAMs (1103 PMOS, 2105 NMOS)
do not share that pinout.
--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
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