Electronika - putting PDP-11 on your desk and in your hand


With the cloned LSI-11 chip, the К1801ВМ1 and family, the Soviet brand Electonica produced an all-in-keyboard home computer in 1984:

and then in 1986 a handheld computer, the MK-85, running Basic and selling perhaps 150 thousand units selling for just 145 roubles ($230 approx):

See also this technical info site which says it was quite expensive at the price and also very slow:

In normal mode the calculator worked very, very slowly. For example, the calculation of the sine of 3 required whole 3.5 seconds. It was possible to put the calculator in “accelerated mode” by pressing the “+” key. Then the same calculation took “only” 0.5 seconds, but you could see the batteries literally “decay” in front of your eyes, and very soon you had to replace them.

and see also the Russian wikipedia article:


Someone is having fun with these LSI-11 clones over here:

…and someone else is rebuilding these chips in HDL:


Awesome!! Amazing machines, sadly them are really weird in South America.

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Also mind its bigger brother, the Elektronica MK-90! (Thanks to the big screen, you can play Tetris on this one, well before the Game Boy.) – I really do want one of these.

Sidenote: Apparently (I’ve just read this and do not know any specifics) the BASIC implementation on the Elektronica PDP-11 handhelds used BCD arithmetics only and weren’t the fastest for math.

Jamel Tayeb had some beautiful images and even videos on his G+ page, but sadly these didn’t survive the transition to his blog. The texts are still to be found:

[Edited for tablet/autocorrection induced noise.]

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Piotr Piatek’s site has some amazingly detailed information on these machines:

For the MK-85 see, http://www.pisi.com.pl/piotr433/index.htm#mk85

and for the MK-90, http://www.pisi.com.pl/piotr433/index.htm#mk90