Do tell more! How behind was the Soviet Union in computing (if indeed it was behind) compared to other countries at the time?

It was hopelessly behind in hardware. The processors were cloned by thinly slicing them and making pictures. This is how i8086 was "designed" anyway. http://www.cpushack.com/soviet-cpus.html

There was very little original software written at the time, multiple teams were tasked with reverse-engineering popular software tools and programs and translating them into Russian for internal consumption.

The gap in software development is somewhat harder to quantify. Overall the software was rather decent in those rare cases when it was original.

I assume you've seen this. http://micro.magnet.fsu.edu/creatures/pages/russians.html

Neat, though that phrase makes no sense in Russian. It's not even a properly formed sentence.

I think it's good enough for the target audience to have gotten the message if they ever saw it though.

Speaking of things that the soviets reverse-engineered, I think the B-29 Superfortress is worth mentioning: https://en.wikipedia.org/wiki/Tupolev_Tu-4

Did they use a microtome with a diamond knife? Floating slices on water, to grids or slides?

Might grinding yield better resolution?

Such technology might be useful in the process of developing open-source hardware.

As far as I understand, common practice was lapping. Yield was always acceptable.

It is still being done now, for open-source hardware too, like here : http://zeptobars.ru/en/read/KR580VM80A-intel-i8080-verilog-r...

Were they so far behind in VLSI design that decapping and reverse engineering was a better option than re-implementing the processor from a published spec?

They were much less behind than it is now (1-2-5 years max). The problem is that leadership of USSR wanted to take advantage of using existing software - hence demanded 100% exact copy of hardware (starting from IBM-360). By many these actions were considered a treason, especially in retrospective.

There were independent developments, they worked but never went widespread (because they needed an "order" from the state).

I suspect yes, that was one of the reasons. They were likely lacking CAD tools for VLSI design.

Thanks! How compatible were these computers with IBM PCs? Aside from the different codepage, would any DOS software run properly on them? I wonder whether, for example, the CPUs were 100% copies of Intel/etc chips or had minor differences in behaviour.

They were clones of 8088, so fully compatible. I got one at the scrapyard in early 90s and used it till 1996 or so when my family could afford a 386, also plenty pre-loved.

Please post a copy of source code (maybe a masm listing) if you still have it, along with any technical docs. Even though it's 'just another' clone, it's still worth preserving for history.

It never occurred to us at the time that the stuff was worth saving and I left USSR soon after.