What's the rarest or most unusual computer-related item do you own?

Tony Duell ard.p850ug1 at gmail.com
Thu Jan 12 14:15:49 CST 2017

On Thu, Jan 12, 2017 at 8:10 PM, Cory Heisterkamp
<coryheisterkamp at gmail.com> wrote:
> Given the topic, I have this rather *unique* punch card reader, if you want
> to call it that. It is marked EAI but that's where the trail turns cold.
> Perhaps used as a microcode source? All holes are read simultaneously via
> individual switches. If someone has seen one before, please speak up. -C
> http://www.radar58.com/reader/IMG_2894.jpg
> http://www.radar58.com/reader/IMG_2895.jpg
> http://www.radar58.com/reader/IMG_2896.jpg
> http://www.radar58.com/reader/IMG_2897.jpg

Not that exact one, but I have something similar. It reads half a card
(40 columns)
at a time. You turn the card round and put the other end in to read the other 40
columns I guessed.

It has 40 PCBs each with spring contacts and diodes stacked up over the
card slot. And a pair of BIG solenoids underneath to lift the card holder to
the switches.I think it said 'Feedback Data' on it somewhere, a company
I have never heard of.

I got mine as just the bare mechanism with a little PCB on the back containing
the decoder ICs to select a column and a ROM to turn the Hollerith code into
ASCII. About 30 years ago I boxed it up and added a board of ICs to scan
through the columns and output the data serially. And yes, I did get it to scan
1-40 and then 40-1 on successive insertions. so that by inserting each card
twice you got all 80 columns in the right order.


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