Power For An Amstrad Spectrum

If you were an American child of the early 1980s then perhaps you were the owner of a Commodore 64, an Apple II, or maybe a TRS-80. On the other side of the Atlantic in the UK the American machines were on the market, but they mostly lost out in the hearts and minds of eager youngsters to a home-grown crop of 8-bit micros. Computer-obsessed British kids really wanted Acorn’s BBC Micro, but their parents were more likely to buy them the much cheaper Sinclair ZX Spectrum.

Sinclair Research was fronted by the serial electronic entrepreneur [Clive Sinclair], whose love of miniaturization and ingenious cost-cutting design sometimes stretched the abilities of his products to the limit. As the 8-bit boom faded later in the decade the company faltered, its computer range being snapped up by his great rival in British consumer electronics, [Alan Sugar]’s Amstrad.

The Amstrad Spectrums replaced the rubber and then shaky plastic keys of the Sinclair-era machines with something considerably more decent, added joystick ports and a choice of a built-in cassette deck or one of those odd 3″ floppy disk drives for which Amstrad seemed to be to only significant customer. For that they needed a more capable power supply offering a selection of rails, and it is this unit that concerns us today. [Drygol] had a friend with an Amstrad-made Sinclair 128K Spectrum +2 with a broken power supply. His solution was to wire in a supply retrieved from a small form factor PC that had all the requisite lines, and for safety he encased it in an improbably huge piece of heat shrink tubing.

Wiring a PSU to a DIN plug for a retro computer is not an exceptional piece of work in itself even if it’s tidily done and nice to see older hardware brought back to life. What makes this piece worth a look instead is the teardown of what is a slightly unusual footnote to the 8-bit home computer story. We’re shown the familiar Z80 and support chips with the Spectrum edge connector and modulator on a through-hole board with a piece of cutting edge tech for a 1980s home computer, a single SMD chip unusually mounted nestled in a hole cut in the board.

Amstrad eventually stopped making Spectrums in the early 1990s, having also tried the Sinclair name on a spectacularly awful PC-compatible home computer. [Clive Sinclair] continued to release electronic products over the following decades, including a portable computer, the last of his trademark miniature radio receivers, and an electric bicycle accessory. Amstrad continue to make computers to this day, and [Alan Sugar] has achieved fame of a different sort as host of the UK version of The Apprentice. He has not yet become Prime Minister.

We’ve featured another Amstrad Spectrum +2 losing its tape deck for a slimmer machine. On that note, the Spectrum wasn’t Amstrad’s only entry in the 8-bit market, and we’ve also shown you a compact clone of their CPC464. As for [Drygol], he’s featured here several times. His mass-restoration of Commodore 64s for instance, or bringing a broken Atari ST back from the dead.

31 thoughts on “Power For An Amstrad Spectrum

  1. >Sinclair name on a spectacularly awful PC-compatible home computer

    Those were fine in itself, but Sugar got screwed by Seagate and WD. Sugar was a street smart hustler and I suspect he managed to negotiate a deal that was too good to be true, so good in fact both Seagate and WD were unable to actually cover the cost of manufacturing reliable hard drives.

      1. No, it was really the other way around. According to the autobiography of Alan Sugar both Seagate and WD shipped them defective drives but claimed the problem was Amstrad’s own HDD controller. One of them even shipped them drives which were returned defective by another computer manufacturer. So Amstrad was the victim of fraud here.

          1. I get your reasoning but I don’t agree. I don’t think Sugar is overly rude, he is just a no-nonsense business men who likes to be very direct and not putting sugarcoating on everything. One can like that or not. I do like it and I have enjoyed every episode (so far) of the UK version of The Apprentice (I always found it way better than the american equivalent featuring Trump).

          2. Sugar certainly wasn’t a Tramiel.
            He drove a hard bargain, but dealt honestly with his suppliers and workers, but expected them to do the same, and didnt take any sh*t
            Also don’t believe all of what you see on the Apprentice (UK version).

    1. The one I saw didn’t have a HDD. Are we talking the same machine? It was effectively the mainboard of the Amstrad portable PC-XT in a black console case of similar size to an Amiga 500, and it just had a floppy. Priced at Amiga prices IIRC, yet with CGA through a TV set.

    2. I did a full reverse engineer of the +2A and +3 power supplies some time ago and have to admit, there were design failings. To be fair, it wasn’t all bad but if you short a positive rail to a negative one it’ll pop as the fuse is situated on the 0v rail!!

      I would like to share my first efforts with whoever wants it.

  2. That QFP looks very unusual. Perhaps they mounted it that way so that I could be taped in-place and wave soldered without frying it?

    I have a working CPC-6128 here. I use a LCD monitor for it as it’s too expensive to get a screen because of the freight costs.

  3. I had an Amstrad PC that I never got to use because I didn’t have the monitor, and that’s where the power supply was. IIRC it connected to the back of the computer box through a big CPC with a threaded ring.

    1. Yeah, those were a PITA, at one point in the early 90s had a PC-1512 running off it’s screwed up mono monitor with a IBM CGA connected…. though later it got the cable cut off it and spliced to a power brick that was literally about dimensions of house brick, some strange 200W or so not very AT shaped, but ATish PC PSU that I got for cheap.

    1. The RS232 ports use +12v as well, but you can dispose of that if your not using them. (And I suspect the number of people who actually ever did use them could be counted on one hand)

  4. Correction.” British kids really wanted Acorn’s BBC Micro” is wrong. We all wanted spectrums as that had all the games. Some of my friends got a BBC micro which was soon replaced with a Spectrum. The price point helped but if you did not have a spectrum at school you would be on your own, all the other kids swapped C90’s with ripped games. :)

    1. It was more like the BBC was the one your parents wanted you to have, but the Spectrum was what they could afford…. get something like 4 speccys for the price of a beeb and you’d still be stuck loading from tape unless they forked another few hundred for drives.

  5. > its computer range being snapped up by his great rival in British consumer electronics, [Alan Sugar]’s Amstrad.

    This is quite misleading I would say. According to his autobiography Sinclair was in deep trouble and would have become bankrupt if he would not have stepped in. He describes how he was dragged and begged into rescuing Sinclair so “snapped up” is technically true but not to the real meaning.

    1. Yeah but do you trust Alan Sugar to tell the full truth? In a way that doesn’t make him look like a fantastic hero?

      Not saying he’s lying there, got no idea. Just going from The Apprentice. Of course he uses a put-on personality for TV, but that personality is a dick. Of course that’s required, but a TV personality is usually based on your real one. He’s not a great actor, mind, he does come across as a bit of a plastic businessman, an unconvincing combination of Gordon Gecko and Scrooge McDuck.

      His success is due to knowing his market. Contracting manufacturing out to get stuff made very cheaply, but having the appearance of only being slightly cheap. Low-end stuff with a nice shiny case, and a bit of hype.

      One thing he did well was the Amstrad PCW, a Z80-based machine with very simple hardware, apparently the mainboard of it’s successor the PCW16 was the size of a credit card. Just the CPU, a ULA, ROM and RAM (just like the ZX81 actually!). Came with the 80-column mono monitor and floppy drives in a one-piece case, keyboard on a wire. Then a printer, daisywheel or dot-matrix, stripped down and brainless, the printer’s hardware controlled directly by the main machine’s CPU. Actually that’s another Sinclair trademark!

      It’s key to success was to be an appliance, a word-processor, and not a computer. Of course it was a computer but didn’t require operating like one. It came with a CP/M disk that most users probably never used, and the main word processing program, Locoscript. Bare minimum, but a capable word processor designed around computer-illiterate people who needed to type stuff and print it out, my Mum got one when she became a student.

      It must’ve had an enormous profit margin, really not much in there. Power supply shared with the printer. Really cut down hardware so the software did all the work.

      Later on came the PCW16. A Z80 at 16MHz! Ah, you thought it’d be 16-bit didn’t you! Ran a really simple sortof windowing system, a mouse with menus and buttons to click on. No multitasking, again, just an appliance. But by that time technology had moved on, and people wanted PCs. And the Z80 wasn’t quite up to the task. I think the Z80 was embedded in the main ASIC, actually.

      Apart from that, cheap stereos, cheap videos, and the contract to supply millions of decoder boxes for Sky, Britain’s only satellite TV operator (apart from one competitor that lasted 15 minutes and nobody remembers). They were pretty cheap too. People will pay half-decent prices for just-about-adequate products. Not utter cheap shit (though before Ebay and China’s manufacturing boom there really wasn’t any of the absolute shit you get now), but pretty bottom-end of respectable. Again, I bet his profit margins were amazing.

      So, he started off as a barrow-boy and pretty much remained one. The barrow just got bigger.

  6. I really love those freakin flex ATX PSUs, recently I put one of them into a Sun SPARCstation LX, old (original) PSU kicked the bucket and replacements on ebay (see: expensive!) are old and used, one of them died too…

  7. ”British kids really wanted Acorn’s BBC Micro”

    The only kids I knew with BBC Micros or Acorn Electrons were teacher’s kids, and that’s because their parents were exposed to them most in work.

    Most kids wanted the same as their friends had, and that mostly meant ZX Spectrums & Commodore C64s with a smattering of Amstrad CPCs, especially in places where there were Amstrad dealerships which let kids play on the machines after school had finished.

    Just in my experience, obviously, but I’ve only ever heard the ‘Acorn versus SInclair’ thing from, say, BBC’s Micro Men TV film – which they arguably had a stake in showing that way.

    1. Yup.The BBC Micro was terrible! It had just 32K RAM, of which 20K was needed if you wanted the full-colour mode. Terrible, stupid design! Ther other 32K was ROM, an overdone (though very good) BASIC. On most kids’ computers, the only BASIC ever interpreted was LOAD “”.

      Then, of the 16 colours in that 20K, half of them were just flashing combinations of the first 8. Red / cyan, blue / yellow, ie a colour and it’s RGB inverse. At least sticking a few more shades in there, doubling the palette from it’s 8 simple primaries, would’ve helped. Even the Spectrum had 15 colours (the brighter black still being black).

      Terrible, awful computer for kids (ie for games). Nice I suppose if you were into adding things on to it, the OS supported extensions well (though so did the Spectrum). But almost no kids ever bought peripherals beyond joysticks and the tape recorder.

      I suppose the BBC was good for education, it’s BASIC was very good, probably the best on an 8-bit, though some other 8-bit BASICS were more than good enough. The BBC had LOGO too, which we used at school, a good way of getting kids into learning programming. I’m surprised schools still don’t use it, seems a lot more useful than those pluggy-jigsaw things they give them now. LOGO is limited to drawing graphics (well, as far as it’s design purpose and style goes), but once kids get the idea of it, it’s easy to move onto BASIC or whatever else. Then from there to C at college if they want to.

      The 8-bits were also good for learning ASM, since you had the whole machine, you could use OS functions if you liked, or ignore them. No other software to respect or fit in with. That’d be good experience for moving onto microcontrollers, which are pretty similar in practice, and in architecture. I really think the Spectrum at home, and BBC at school, were a great aid, and the Spectrum is largely credited for Britain punching so much above it’s weight in the computer games business. Their lack, now, I think is a disadvantage. The Micro-Bit and Ras Pi I suppose are partial replacements.

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