Interesting HP41 module on ebay


See page at:

I wonder if it was meant to be an electronic version of an enigma type machine?

I have not seen a removable rubber overlay that is shown for the HP41.

Please note that I have no connection with this item.


I contacted the seller and as a remark: He sells the EPROM with the overlay I think. I´m not shure if he sells also the HHP EPROM box!

Happy bidding


Some time ago I heard persistent rumors that during early 80s some crypto gear disguised as HP calculators were supplied to some Soviet defense scientists/engineers who spied for US CIA/DIA - a guy like A.G. Tolkachev comes to mind (eventually caught by KGB & shot circa 1985?). (There was apparently another small radio device that allowed shorter, secure messages to be conveyed up to 1/4mi to avoid face-to-face agent contact and was separate from this.)

I had heard somewhere it was a 41 (after all, it was alphanumeric!) but even if that was wrong, other hacked numeric-only calcs that could deal with something like 5-digit code groups could work too.

An HP sci calc at that time would be a piece of equipment that although uncommon and pricey would not be odd or out of ordinary and at the worst could be 'explainable' in an investigation as a blackmarket purchase but would be tolerable for a senior guy...

Bill W
San Jose CA

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