I am familiar with the original ZX80 and its "cousin", the Jupiter Ace, a similarly specc'ed machine but running Forth rather than BASIC.

However, a colleague at work stated that there had been a machine called the MicroAce and I suspect he was simply conflating two machines.

Was this a real machine and, if so, how did it differ from the other two? I suspect, even if it was real, it was simply a rebranding much like the Timex Sinclair 1000 was for the ZX81.

  • 3
    According to en.wikipedia.org/wiki/MicroAce "it was an unlicensed clone of the Sinclair ZX80 and had an identical, yet obfuscated copy of the ROM by means of a byteswap". Mar 21, 2022 at 23:49
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    I imagine the name "MicroAce" (or those similar to it) has been used many times for different products. For example, a Philippine company named Alexan used to sell a microprocessor trainer called the "Micro-ACE" in the early 1990s. (I forgot which microprocessor it had, probably a 6800.)
    – JRN
    Mar 22, 2022 at 1:08
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    See timexsinclair.com/computers/microace
    – JRN
    Mar 22, 2022 at 5:28
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    Why are these being posted as comments when they're clearly answers? The whole point of the SE sites are to provide answers to questions, commenting on things is best left for clarifications or suggestions.
    – paxdiablo
    Mar 22, 2022 at 6:50
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    @paxdiablo - I guess because it's too easy, and too close to a single-link answer ;-) Mar 22, 2022 at 8:08

1 Answer 1


It's possible your colleague misremembered or conflated two names. After all, the prefix Micro- is common enough in computer-related branding (see also the MicroBee, Microtan 65, and others).

It's also possible your colleague meant the MicroAce, which was an actual clone of the ZX80. This one was probably made well-known by the court case around the software copyright. Sinclair and the makers of MicroAce ended up settling out of court, and MicroAce carried on selling in the US, separately from the Timex Sinclair 1000, which was a licensed ZX81 clone.

Was this a real machine and, if so, how did it differ from the other two [, being the ZX80 and ZX81]?

It was ZX80 compatible, so a little different from the Timex Sinclair 1000, which was ZX81 compatible. Here in the UK, Sinclair stopped selling the ZX80 after the ZX81 was introduced to the market. But in the US, both the MicroAce and the TS1000 kept on selling contemporaneously (not so surprising, since they were being sold by two different, independent companies).

There is not much difference between the ZX80 and the MicroAce. The only difference is that the MicroAce can be upgraded to a whole 2 kilobytes inside the case. Oh, and the ROM is different as well, but that's just because two of the data lines have been swapped over. So you can't just drop in a ROM from a ZX80 and have it work. But this change is so trivial. Not enough of a difference to convince the judge of that court case.

  • If I still had access to a law library, it’d be interesting to look the case up. Arden, etc, manage to assert copyright over things like their collections of Shakespeare text — even if severed from the copious footnotes — on the premise that they’ve adjusted things like the punctuation (which varies even in contemporaneous folios). I wonder to what extent the automated adjustment here negated any similar argument, if it was made. That is, given the extremely early nature of the argument, when IP over software was still far from settled.
    – Tommy
    Mar 22, 2022 at 21:49
  • @Tommy: I suspect that the obvious purpose of trying to evade copyright counted against it. Mar 22, 2022 at 21:57
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    Swapped data lines ... that reminds me of a VAX compatible machine (cant remember the type) which had simply swapped the nibbles of the opcode (first byte) in order to avoid a similar court case with DEC. Worked on on in the early 80s in Israel, but can't remember neither company nor model.
    – Raffzahn
    Mar 23, 2022 at 17:30

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