A Redesigned ZX Spectrum Desktop Computer That Works Surprisingly Well

Retrocomputer enthusiasts will quite often be found pondering the great what ifs of their hobby. What if Commodore had had a half-way decent marketing division is a popular one, but the notoriously penny-pinching ways of Sinclair Research are also a plentiful source. What if Sinclair had won the competition for a computer in UK schools, not only the first time around when Acorn’s BBC Micro scooped the prize, but also what if they’d entered the fray once more in 1983 when there was another chance? [10p6] investigates this possibility, and comes up with a Spectrum desktop computer that you can see in the video below the break.

The first two-thirds of the video is devoted to renders which, while pretty to look at, offer nothing of substance. In the later part though we see a build, putting a Spectrum 48k board, Interface 1, and two Microdrives in a slimline case along with a power supply. Meanwhile a ZX rubber keyboard is mounted stand-alone on the end of a cable. It’s a computer that we know would have been an object of desire for many kids back in the day, and we agree with the video that it could have been integrated onto one board without the need for a separate Interface 1. We feel it’s inevitable though that Sinclair’s cost-cutting would have caused something to go astray and there would certainly have been only one Microdrive, even though we like that separate keyboard a lot.

They claim that the STLs will be available from a Facebook group, however unless you happen to have a set of Microdrives and an Interface 1 to go with your Spectrum that you’re prepared to butcher for the project we’re guessing that the chief interest lies in watching it unfold and that some of the ideas might translate to other platforms. Meanwhile if you’re interested in the Microdrive, we did a teardown on them last year.

18 thoughts on “A Redesigned ZX Spectrum Desktop Computer That Works Surprisingly Well

  1. Unfortunately, Microdrives are a dead end street. the tape cartridges use a small block of felt to press the tape against the playback head. That piece of felt inevitably crumbles to dust and this kills tha cartridge.

    Fortunately, nowadays there are plenty of alternatives like flashcard and HD interfaces.

    1. It would be fun to do something like what they did with the SD2IEC (where they made little replica 1541 housings for it), and make an SD card carrier shaped like a Microdrive cartridge.

      BTW, the felt disintegration is repairable, but often causes a tape breakage. And it’s not worth repairing the carts anyway, unless there’s data you desperately want to recover.

      1. The left side drive on this is a VDrive. The ULA on the Spectrum and Interface 1 have both been recreated now too, and technically they both could be put on one chip to make a much smaller all in one pcb.

    2. The look was different but some revisions of third party keyboards like the dktronics would actually comfortably accommodate the main board, a replacement keyboard interface 1 AND the power supply in an all in one unit.

      Visually though you’d probably have been looking at something more like the QL.

    1. The idea for back in the day would be to keep with Sinclair’s pattern of cheap and reusable. I played with a mini Cherry Keyboard which is awesome, but back then other than for teachers, it would have been unlikely used for kids due to its cost.

      1. Yeah, I just didn’t know which would be a better choice for school, expensive but unbreakable, or cheap enough to be a consumable. Anyway the nice think you have done is when people copy your design they can decide what keyboard they want, the “students” of the “teachers”.

        1. Back then it would have been easy to have several styles of keyboard since it contained no electronics. Like the one I show, maybe a full travel rubber dome compact version, and a full size mechanical keyboard…. The only thing I would have done different is on the kids version, made it so the connector could have been pinned or screwed in to stop kids hacking in 13 pin keyboard to joystick connectors for when no one was looking.

      1. Unfortunately the Spectrum requires 13 lines for the keyboard, or they would have to include multiplexing IC’s which would add to the cost, especially if the IC is in the keyboard as it would then have to be larger and have a PCB as soldering IC’s on flex then was not a thing.

  2. The microdrives were the biggest mistake on the Spectrum. No way to exchange data with other computers of the time. While at that time, it was already well established that even though computers were very different and couldn’t run each other’s programs, they *could* use each other’s data. It’s why every computer manufacturer made efforts to be able to at least read data from floppies created on different systems. The Atari ST, the Amiga, PC’s, Apple Mac (ok, with an add-on drive), they could all read dos-format floppies, some could write them too. But try to read a dos-format floppy with a microdrive… :P

    1. You have to remember the Spectrum was released years before the Amiga / ST / PC, and the ones for the C64 and Atari 400 / 800 range cost a fortune; I went to well funded Catholic school and even in 1985, we only had a couple of
      Floppy drives for a class full of BBC’s.

      Whilst the Microdrive’s were not the best solution, they did a semi decent job for a fraction of the cost of a 5 1/2 drive. If my system had been made, then the kids OPC would have probably not even had a drive and data would have just been networked, or maybe they may have had a Interface 2 style Rom Port. That is why I said the Teachers unit would have had a bottom expansion connector for a stackable Floppy or Hard Drive.

      Note that a 5 1/4 Floppy disk is 2/3rds the width of the OPC.

    2. The Spectrum came out in 1982, the microdrive the next year.

      In 1984, I spent $500 Canadian on a floppy drive, case and power supply, and floppy controller card for my Radio Shack Color Computer. The computer cost less. A box of ten floppy disks cost fifty dollars.

      Home computers couldn’t be cheap at those prices. Which is why audio cassettes were used by many in the early days. Not a great choice, but cheap (not just the cassetterecorders, but the blank tapes, and the interface tiny), and it beat typing in a program every time you turned on the computer.

      Beause if their failings, people looked for better things. Saturation recording, better cassette drives which could be computer controlled. The stringy floppy, using minicassettes, a whole drive which started to be closer to the price of floppy disks, especially because things moved fast. What was expensive in 1984 was “cheap” in 1989; I’d gotten a second drive by then, I think fifty dollars, and a 3.5″ that year for somewhat more.

      Aome of the cassette schemes were more about retrieving files, rather than increasing speed or reducing error. But you needed a better mechanism, so thecost went up.

      So for the time, microdrives made sense.

      I didn’t get a hard drive till the end of 1993.

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