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The KR580VM1 (or КР580ВМ1) is a CPU from Soviet Ukraine that is not directly equivalent to any Western ones. It's basically an Intel 8080 with another register pair, H1L1, and another address space which can contain data but not executable code. Instruction prefixes control the use of H1L1 and the second address space.

Sounds like a great product, right?

The thing is I cannot find any evidence that this chip was ever used anywhere by anyone. Maybe the Z80 clones plus bank switching mechanisms eclipsed the KR580VM1's usefulness. Maybe it was used only in embedded applications that nobody writes about today. So my question is if this CPU actually was used in any products

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    If it were used in items for the Soviet military, finding information about that might be difficult.
    – RichF
    Dec 23 '20 at 11:58
  • @RichF Good point. I think the Soviet military mostly use domestic CPUs (mostly BESM6/Elbrus type stuff), I guess the 'VM1 could fit in that category
    – OmarL
    Dec 23 '20 at 12:03
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    Some Вектор-06Ц are known to be fitted with a КР580ВМ1 - which is easy as it is in Mode 0 mostly compatible with the default КР580ВМ80А. The Virtual Vector emulator does support the КР580ВМ1 extensions. --- And no, I do not own any of them :( --- BTW, the КР580ВМ1 was not made in (Sowjet) Russia, but Ukraine, by "Квазар" (Quasar) in Kiew.
    – Raffzahn
    Dec 23 '20 at 14:54
  • @Raffzahn it seems like a start to a good answer.
    – OmarL
    Dec 24 '20 at 8:59
  • Not sure as it doesn't show any that has been made do from the start. While proving otherwise is impossible. I'll copy it into an answerand lets see that else comes up.
    – Raffzahn
    Dec 24 '20 at 11:32
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Sounds like a great product, right?

It does. 64 KiB code + 64 KiB data is about the ideal structure for an 8 bit CPU with 16 bit addressing.

The thing is I cannot find any evidence that this chip was ever used anywhere by anyone.

It came not only late, but as well at a rather troubled time, followed by an extreme fast swing to simply by world standard CPUs.

Maybe it was used only in embedded applications that nobody writes about today. So my question is if this CPU actually was used in any products

None that I know of. But there are reports of Вектор-06Ц (Vector-06Z) to be fitted with a КР580ВМ1 - which is easy as it is in Mode 0 mostly compatible with the default КР580ВМ80А.

The Virtual Vector emulator does support the КР580ВМ1 extensions.

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  • "It came not only late", do you know when?
    – OmarL
    Dec 24 '20 at 17:49
  • @OmarL Not exactly, must have been 1988..90. much like a stop gap before going to 16 bit.
    – Raffzahn
    Dec 24 '20 at 18:48
  • Also, Mode 0? Implies there are other modes, not compatible with the вм80. I have found anything about that. Are you able to elaborate?
    – OmarL
    Dec 31 '20 at 19:18
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    @OmarL Not really. It's a bit like with the 8086 min and max mode. like there mode select is done by pulling a pin. The VM1 is in Mode 0 (mostly) like an 8080 pinout - except not needing -5 and +12 Volt and Phi2. -5 is turned into the mode select and PHI2 now carries a M/IO, while Mode 1 is closer to an 8085 in offering an INT/INTA interrupt mechanic. and ready instead of wait. and ofc A16 to select the memory spaces.
    – Raffzahn
    Dec 31 '20 at 20:38

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