Sorry if this is off-topic - it's not an HP calculator, but it's RPN and it's programmable, and it's old so it fits in a museum site! :)
I have one of these beasts and it's really interesting - lots of "hidden functions", illegal opcodes and the possibility of synthetic programming... Nice for a nerd! :)
Anyway, I managed to learn the basic use, but I really need a manual and I can't read Russian. I found a "functions table" in English, but no complete manual. Does anyone know if such a translation exists somewhere?

Thanks,
Cristian

You probably know: http://www.alfredklomp.com/technology/mk-61/
I have also one ;-)

Regards

And also: http://www.taswegian.com/MOSCOW/mk-61.html and http://gregescov.tripod.com/keys.htm

Yes, I knew those pages, but thanks anyway because it was interesting to re-read them after a long time! :)
They were very useful because they enabled me to start using the calculator; but I'd like to be able to take advantage of the (supposedly very good) full manual...

Cristian

I have an MK-61 as well. Did you also get the complete electrical schematic diagram sheet with it ?

Shortly after my post above, I picked up a very clean looking Elektronika MK56, which is the desktop equivalent to the MK61. It also has a green VFD display and runs directly from a 220 vac mains.

Hehe, and I just bought a MK52, which is functionally the same but in landscape format (!) and with a "persistent memory" - supposedly the only calculator ever with an onboard EEPROM for program storage - and an expansion port. Fascinating machines! :) I love to disassemble them and see how different soviet electronics looked back then... Now they look the same as western ones, but then, now everything is made in China! :)

Mine did not come with a schematic, I don't know if it is a later build (the manual got progressively simpler and smaller with time) r if the previous owner just lost it.

Cristian

My MK61 came in a box with a 208 page manual, the schematic, AC adapter, soft slip case and calculator. The back is molded 92 06, so I assume it means that it was manufactured in June, 1992. Also, several pages in the back of the book are stamped and hand written 12.10.92, which suggests that it was sold on 12 October 1992.

Mine is marked "88 10" so it's older than yours, I suppose this means the original owner just lost the schematic. But I downloaded it somewhere. Though I'm not at the point where I'd need a schematic yet... I'd be happy enough with a usable (for me) manual! :)

Cristian

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Hehe, and I just bought a MK52, which is functionally the same but in landscape format (!) and with a "persistent memory" - supposedly the only calculator ever with an onboard EEPROM for program storage - and an expansion port. Fascinating machines! :) I love to disassemble them and see how different soviet electronics looked back then... Now they look the same as western ones, but then, now everything is made in China! :)

Mine did not come with a schematic, I don't know if it is a later build (the manual got progressively simpler and smaller with time) r if the previous owner just lost it.

Cristian

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My favourite Elektronika calculator has to be the MK 54, which was a clone of the B3-34 (Elektronika's first really big programmable) in a case identical to the MK 61's. Since the B3-34 only had one shift key and the MK 61 has two, this means that the MK 54 has a shift key that isn't used by any function of the calculator.

The key is not, as you might think, just not connected to anything, however. Using it before any function will give a familiar-to-any-Elektronika-user `eggog'.

The MK 52 might be the only calculator to have EEPROM storage, but the MK 54 has to be the only one that has an error button.

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The MK 52 might be the only calculator to have EEPROM storage, but the MK 54 has to be the only one that has an error button.

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I'd heard about that calculator, and of its incredible "Error" button! :)

I've been experimenting a lot with my MK61, and I'm starting to wonder if maybe I have an unusual ROM revision... because some of the procedures needed to enter some of the weird, unofficial, "hacker" modes give unexpected results (while the emulator and other people's 61s work as expected). Instead of being able to enter some illegal opcodes or numbers, my calculator enters a weird, semi-unstable state which I don't understand (yet). And I have no idea why.

It's a shame that with all the huge amount of articles and documentation about these programmables published in Russian, almost nothing has been translated, or is available in any way...

Cristian

Since here seems to be a MK-xx fanclub ;-)

Do you know this site:

http://www.pisi.com.pl/piotr433/

It has many infos (and emulators!) for the MK-85 and MK-90! :-)

Franz

There is no unused prefix button on MK-54. If you mean blue "K" button, then it is used as indirect prefix for some functions -e.g.
K ∏->x is equivalent to RCL (x). (∏ stands for Russian P, which looks like Product symbol or inverted U, so K U->x.)

Strange behaviour of MK-54 is frequently caused by unstable power (check oxidized contacts) or instability of generator. There are lot of information on Russian sites.

Edited: 11 Oct 2011, 5:18 a.m.

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There is no unused prefix button on MK-54. If you mean blue "K" button, then it is used as indirect prefix for some functions -e.g.
K ∏->x is equivalent to RCL (x). (∏ stands for Russian P, which looks like Product symbol or inverted U, so K U->x.)

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I'm also not sure I'm following what you're saying. In the example you give, the K shift button isn't being used as an indirect prefix. Unless I misunderstand you, you're saying that it's acting as a NOP, because the unshifted Π -> x key does what you're describing.

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I also note that the Elektronika calculator emulator I have doesn't reproduce the behaviour you describe on the MK 54.

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That might not be meaningful - I found out that the emulator is not really an emulator, but a simulator - it doesn't use the original firmware of the actual calculators. For example, it doesn't handle "Zggog" on the 61...

Cristian