44 votes
Accepted

Using DRAM as a camera sensor?

That sounds a lot like the Cromemco Cyclops. Released in 1975, it used a modified1 MOS 1kbit DRAM2 to capture a 32×32 black and white or greyscale image. The memory cells were initially set to all ...
Alex Hajnal's user avatar
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13 votes

Using DRAM as a camera sensor?

Alex Hajnal's answer pretty well describes what I believe is the first and eventually only commercial available camera that directly used RAM chips, the Cyclops (*1). It started out as a hobby level ...
Raffzahn's user avatar
  • 223k
8 votes

Using DRAM as a camera sensor?

We tried it in the lab, circa 1984. I worked with a hardware team and somewhere they'd read an article, the gist of which was something like: write all 1s to the DRAM ensure you don't have any ...
jonathanjo's user avatar
7 votes

Using DRAM as a camera sensor?

Sorry to come late to this party. One thing to note is that, in order to use the DRAM in the way that the Cromemco Cyclops does, it must be a design with a non-destructive read. The 4008 parts (both ...
William Sudbrink's user avatar
7 votes
Accepted

Why do Early DRAMs (e.g. 4116) have a negative Column Address Set-up Time?

The 4116 was likely designed during in an era (or semiconductor technology node) when self-timed-delay pre-charge-evaluate NMOS logic cascades were common. (e.g. rather than synchronously or edge ...
hotpaw2's user avatar
  • 8,183
3 votes

Using DRAM as a camera sensor?

Back around 1982, 1983 a friend of mine built a simple scanner using a 16k de-capped dram, probably a 4116. This was used on a Nascom 2 computer with a Nascom IMP dot matrix printer. The dram, along ...
Tim Ring's user avatar
  • 406
2 votes

Using DRAM as a camera sensor?

As others have pointed out, the Cromemco Cyclops turned this into a (hobbyist) product. I've also found I could get reproducible transient bit flips in an unprogrammed EPROM. Shine a laser pointer ...
jeffB's user avatar
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2 votes

Why do Early DRAMs (e.g. 4116) have a negative Column Address Set-up Time?

I will venture a guess. Imagine /CAS and the address bus are both registered outputs clocked by the same clock. The negative setup time allows a slight clock-to-output propagation delay discrepancy ...
Zane Kaminski's user avatar
1 vote

Why do Early DRAMs (e.g. 4116) have a negative Column Address Set-up Time?

(Preface: leaving out the title column makes reading tables it a bit hard) It's all about translating labels and numbers into meaningful sentences. And there are different ways to tell a fact, and ...
Raffzahn's user avatar
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