[ Retro Scan of the Week ] Memotech ZX81 Modules

November 3rd, 2014 by Benj Edwards

Memotech Sinclair ZX81 Timex-Sinclair 1000 expansion modules advertisement - 1983Extend your ZX81 a full ten inches

The Sinclair ZX81 (marketed in non-kit form as the Timex-Sinclair 1000 in the US) was a tiny computer with a tiny price and tiny capabilities.

It was possible, however, to make up for some of those shortcomings with a wide array of plug-in peripheral modules from Memotech, seen here in this ad from 1983. Furthermore, by piggybacking one module onto the next, it was possible to create an even more capable — and far longer — ZX81.

I wish I had some of these Memotech modules to mess around with. All I have is the bulbous Timex-Sinclair 16K RAM Module. Time to check eBay.

[ From Personal Computing – November 1983, p.18]

Discussion Topic of the Week: What’s the smallest non-portable computer you’ve ever used? (e.g. Timex-Sinclair 1000)

8 Responses to “[ Retro Scan of the Week ] Memotech ZX81 Modules”

  1. Dennis Says:

    I do own a TS-1000, but I would have to say the smallest non-portable computer that I’ve used would be the Raspberry Pi. Otherwise, it would be a close call between the Mac mini and the TS-1000.

    I should pull out the TS-1000 again sometime. I never really did that much with it, since I had other more capable machines around to play with. But it was an interesting little device, especially given for how cheap it was towards the end of it’s retail life.

  2. Calibrator Says:

    I had a 16K Memotech RAM as advertised for my ZX-81 and it had a nice, solid metal casing. It even smelled kinda nice but I don’t know if that posed a health risk. 😉
    It was comparably heavy module, perhaps even heavier than the ZX itself and that was the major problem with it:

    It was just plugged in onto the ZX mainboard (no real connector on the ZX for cost reasons of course) and it was a pretty wonky affair as I found out when I typed in a lenghty listing from a magazine and a friend came into my room and slightly nudged against the table my ZX was sitting on.
    The end result was that the RAM lost all of its content in a second, which had been typed in for about two hours and which I hadn’t saved to tape, yet…

    I was totally depressed and my friend, only slightly remorseful, told the story many times so it at least remained fresh in my own memory!
    So, the morale of the story is: Save early and save often – especially if you use a cheap computer!

  3. Jistuce Says:

    I love how some of those Memotech expansions cost as much as the computer they attach to. Especially the keyboard, there’s a certain hilarity inherent in paying as much as the computer costs to attach a decent keyboard to it.

    @Calibrator: To my understanding, that’s a problem with the ZX-81 regardless of the expansion module brand. At least the Memotech one had the decency to be low-profile so you were less likely to hit it with your hand.
    And, well, at least it’s a cheap computer. There’s some much more expensive devices with the same problem.

  4. Moondog Says:

    @ Jistuce: I also like how the “accessories” cost as much as the computer itself. Memory and drive space were historically expensive until recently. When a budget home computer sold for $200, it really wasn’t much use until you spent 2 or 3 time it’s price adding external drive storage, a printer, and other upgrades. Fortunately prices have gone down, and the “hidden” costs of home computing are history.

  5. Daniel Says:

    I still have a Sinclair ZX-81, and I have a 16KB memory pack for it (not the Memotech one, but one about the size of a large power brick. I haven’t powered it up in at least a decade, so it’s probably dead now, but man that was a neat tiny computer back in the day.

  6. Calibrator Says:

    > I haven’t powered it up in at least a decade, so it’s probably dead now, but man that was a neat tiny computer back in the day.

    I wouldn’t be so sure that it doesn’t work – you should really try to find out!
    While my ZX was dead after less than a year (I bought a graphics expansion board but probably made an error installing it) all my other old computers still run well and all consoles, too, including the really old ones I got from Ebay about ten years ago.
    Granted, an Atari 400 is much more solid than a ZX81 but many of the problems come from internals like dead capacitors and back then the machines featured less “planned obsolescence” than hardware made today.
    Nothing lasts forever, though, so the worst that would happen is that you get a black screen when a custom or RAM chip bites the dust.

  7. Magnus Says:

    I had a C64 to learn Logo, but then in the late 80s had to sell it to buy a PC XT to be able to use Wordstar, GWBasic and play Alley Cat 🙂

  8. John Says:

    I also have a TX-1000 and few expansions. My junior-high science teacher had a ZX-81. He used to pull me out of another class during his free period to write various little BASIC programs for him. I wrote things like grade-averaging programs, basketball stats tracking and a program to record and tally the results of a beauty pageant our school ran every Fall. Much fun!

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