back to article Infinite loop: the Sinclair ZX Microdrive story

They would, Clive Sinclair claimed on 23 April 1982, revolutionise home computer storage. Significantly cheaper than the established 5.25-inch and emerging 3.5-inch floppy drives of the time - though not as capacious or as fast to serve up files - ‘Uncle’ Clive’s new toy would “change the face of personal computing”, Sinclair …


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  1. Anonymous Coward
    Thumb Up


    Amazingly people are still recovering data from Microdrives today, proving that they were indeed reliable for archiving data.

  2. Anonymous Coward

    3 inch disc

    The 3 inch disc was actually adopted by Amstrad for the CPC. long before the PCW was launched. By all accounts they looked at 3.5 inch drives but they were too expensive and 5 inch wouldn't have been very elegant to build into the case (Sugar insisted the drive must be integrated). Sugar managed to source a supply of 3 inch drives and the rest is history.

    As for me spelling it "disc" rather than "disk", well that's the spelling Amstrad always used with reference to the format.

    1. Anonymous Coward
      Anonymous Coward

      Re: 3 inch disc

      I liked Acorn's approach:



      Both work.

      The issue with the mounting of the 3" disk in the PCW was that it was next to a CRT monitor and this by all accounts wasn't very good for magnetic media.

      1. Anonymous Coward
        Anonymous Coward

        Re: 3 inch disc

        Amusing, possibly apocryphal story. The reason Amstrad used "disc" was because this is what was written on the back of the 464. It was actually supposed to be "disk". However creating new casing moulds would cost money so Sugar vetoed it and kept it as the "British" spelling.

    2. Spoonsinger

      Re: Sugar insisted the drive must be integrated

      My FD-1 wasn't integrated, and I'm fairly sure I got that quite sometime before the 664 came out - from WH Smiths of all places.

      1. Anonymous Coward
        Anonymous Coward

        Re: Sugar insisted the drive must be integrated

        The 664 was already in mind when they bought the FD-1 out. It's just it was quicker to get a peripheral to market than a whole machine.

    3. Jan 0

      Re: 3 inch disc

      Of course it's "disc". The word "disk" is a contraction of "diskette" (an IBM invention). There is nothing particularly British about "disc".

      I'd always thought that the Microdrive had a continuous loop that was sort of folded inside the case. (Not with creases, but taking a sinuous path). What was that kind of tape drive called?

      1. alcockell

        Re: 3 inch disc

        You might be thinking of a drive type that was released during the same timeframe - the BBC Micro had the Phloopy.

        I remember Ian Macnaught-Davis reviewing these on Making The most of the Micro back in the day..

      2. dajames Silver badge

        Re: 3 inch disc

        Of course it's "disc". The word "disk" is a contraction of "diskette" (an IBM invention).

        The derivation of "disc" is from the Latin discus so a 'c' seems a natural spelling, but US English and IT usage have always preferred 'k'. The 'k' spelling is earlier than the first use of "diskette", though, so you're wrong that "disk" is a contraction of that.

        I first came across the 'k' spelling in Patrick Moore's writing on astronomy -- before I ever used a computer -- in phrases such as "with even a small telescope you will be able to make out the disk of Jupiter". It struck me as strange then and I stuck resolutely to the 'c' spelling for many years.

        You're right, though, that "diskette"is the problem. If you write "disc" with a 'c' switching to 'k' for "diskette" just looks silly. What option does that leave? "Discettte"? Yuk. "Disquette" is better, but barely.

        No: Best to adopt the spelling "disk", which is already current in much of the world, and be consistent with "diskette".

        1. K.o.R
          Paris Hilton

          Re: 3 inch disc

          I always think of it as: K is kind of a "square" letter and so it fits with the things that are square in appearance, i.e. hard disks and floppy disks (even though there is still a circular thing inside them, the bit you see is square/rectangular). Conversely, C is a "round" letter and so it fits with the things that are round in appearance, i.e. compact discs, digital versatile discs, blu-ray discs, etc.

  3. SteveCarr

    Ah, the Microdrive...

    My ICL OPD had not one, but two, of these wondrous beasts - that and ROM slots for canned programs. Those were the days!

    1. Professor Clifton Shallot

      Re: Ah, the OPD...

      My Secretary Is On My Extension.

      And other such hilarious manipulations of the text-to-speech facility.

      What a great machine the OPD was. Integrating phone and PC for office workers is still something that needs doing properly.

      1. Ralph B

        Re: Ah, the OPD...

        > hilarious manipulations of the text-to-speech facility.

        May I refer my learned friend to an ancient Reg competition?

    2. Jim Halfpenny
      Thumb Up

      Re: Ah, the Microdrive...

      Remember, your OPD was basically a Sinclair QL, hence the microdrive technology. And you are tight, those were the days.

    3. Yet Another Anonymous coward Silver badge

      Re: Ah, the Microdrive...

      My first proper job in the late 80s was on OPDs - they were used in bingo halls to run a national synced bingo game

  4. Tom 7 Silver badge

    Unfortunately it wasnt a lot better than a cassette tape store

    I've even got the tapes for pascal and c for the spectrum somewhere!

    You might say it was ahead of its time (offered features no one wanted) but to most home users it didn’t really offer a cost-effective advantage over a, probably already owned, £12 cassette deck and a note book for marking the counter readings for various bits and pieces. And from experience at a friends was more reliable.

  5. Simon Round


    "and he worked at Argonaut Software to create the Super FX graphics hip used in SNES games"

    Hip? Should that be Chip? Or was this an early prototype replacable Hip for serious gamers developed in conjunction with the NHS.

    1. The Indomitable Gall

      Re: Hip?

      Don't you remember the big walker robots in StarFox? They had hips....

      1. Anonymous Coward
        Anonymous Coward

        Re: Hip?

        Are you thinking of Starglider, not StarFox?

        1. K.o.R
          Thumb Up

          Re: Hip?

          Nah, definitely StarFox (StarWing here in the UK). Carried big pylons and obelisks around Corneria for some unknown reason.

  6. Tom 64
    Thumb Up

    These were great

    I must have had a good one, it was a joy to use and far faster at loading games than from tape (thanks to the interface 1 I had).

    Thanks for the trip down memory lane, reg =)

    1. Crisp

      Re: These were great

      Except that if you forgot and left a cartridge in the drive when you powered the damn thing on, it would wipe the tape.

      1. Crisp

        Re: These were great

        Downvoting me after losing my copy of Ant Attack is just adding insult to injury!

        1. Alan Firminger

          Re: These were great

          I got a microdrive with half a dozen cartridges and the necessary interface. After ten reads or writes each and every cartridge failed. I threw the lot away.

          And on that basis I never touched a QL .

        2. Jamie Jones Silver badge

          @Crisp: Re: These were great

          awwwwww, how about this?

          1. Crisp

            Re: @Crisp: These were great

            Jamie Jones, you are a gentleman and a scholar. Have an upvote on me.

            Paralysed an ant! :D

    2. 2FishInATank
      Thumb Up

      Re: These were great

      LOAD * "m";1;"<program name>"

      I set up little menus to be able to load one of two or three games off each cartridge.

      The trick of repeatedly formatting the cartridge to get the maximum capacity out of them - I'm sure I had some which had a capacity of 99KB.

      Now I need to dig into boxes and find them...

  7. Anonymous Coward

    Good article

    Those days, of creativity and innovation, really were interesting. The microdrives as part of the affordability of the QL, for what it brought to market, meant that I was able to undertake commercial work turning statistical information into graphical reports (wow factor at the time) at a fraction of the cost of other options available at the time, at a time when the cost of alternatives was so high s to be unavailable. So my "ql" sig pays tribute to the system that started my time making a crust from IT.

    The microdrives on the QL could be used as a swap file for large documents. A couple of years ago, I fired up a QL and found documents from the mid 80s on microdrive could still be read.


  8. Jess--

    anyone else remember the Plus D system on the spectrums?

    3.5" floppy interface and a centronics printer port, 4 seconds to load a full game from disk seemed amazing

    1. Anonymous Coward
      Anonymous Coward

      Owned both one of the these and Microdrive.

      +D was a great little device from the company that went on to create the amazing SAM Coupe - the last UK home computer until the Raspberry Pi. The PlusD is still being built in emulated hardware on the world of spectrum forums :)

    2. Anonymous Coward
      Anonymous Coward

      Yes - PlusD - thanks for that....

      .... I couldn't remember the name of it! But I'm sure there was another one which did a similar job for floppies...?

      1. Dan 55 Silver badge

        Re: Yes - PlusD - thanks for that....

        The one previous to the +D was the Disciple, from memory it looked much more like the Interface 1 and I think it could also take 5.25" floppy drives. Miles Gordon Technology manufactured the +D, I believe the same designers were also behind the Disciple but maybe in the guise of another company.

    3. gaz 7
      Thumb Up

      I had a +D!

      Was a better deal at the time the Microdrive as I got it half price in Boots cos the box was damaged.

      Moved on from that to a +3 and then to a QL.

      We still have some microdrive cartridges in a data safe at work. Keep meaning to rescue them in case anyone has a mad idea to tidy it. It still has 1/2" reels and manuals for an ICL series 39 that we decommissioned in 1991!

  9. Anonymous Coward
    Anonymous Coward

    There was a video recorder that used a similar spool mechanism to the microdrives. I have a QL and a selection of microdrives.

    The reason for the C64's disk drive costing so much was nothing to do with the cost of floppies. It was down to two things.

    1. Massive demand, the 1541 was impossible to get hold of. Many people (including myself) bought a 3rd party unit instead.

    2. The lack of disk drive functionality in the VIC20 and C64 ROMs. This meant that the disk drive couldn't be a dumb unit controlled by the host computer. The 1541 is a file serving computer with its own 6502 processor. This is obviously a very expensive way of making a disk drive.

    1. Dr_N Silver badge
      Thumb Up

      I never bothered with the 1541 for my C64.

      Picked up a CBM8250 dual floppy drive and an Interpod instead.

      1. GettinSadda

        >I never bothered with the 1541 for my C64.

        >Picked up a CBM8250 dual floppy drive and an Interpod instead.

        Yay - my solution in reverse!

      2. NightFox

        1541 > 8250

        Yeah but you could make the head on a 1540/1541 play "Daisy, Daisy, Give me your answer, do" on a 1541, couldn't do that on a 8250

    2. GettinSadda

      Actually the reason that the 1541 drive is a computer rather than just a dumb bit of hardware is that it is basically a cut-down version of the PET 4040 disk drive which was an IEEE 488 (aka GPIB) devices. The concept is very much like IDE drives, which are what all modern hard drives are at heart.

      The disk interface on the C64 is a serialized version of the parallel IEEE 488 bus and this meant that I was able to build a small interface board for my PET and convert the driver code in the ROM to use this rather than the native interface so I could run a 1541 from my PET.

      1. Anonymous Coward
        Anonymous Coward

        Which is essentially the same reason. They reused old technology for the software on the Vic20/C64 and therefore it had no disk controller or software to handle it. So formatting a disk is something like this:

        OPEN 15,8,15,"N0:NAME,01":CLOSE 15

        Instead of something more friendly like:

        FORMAT "NAME", 8

        They were criticised for sticking with an old version of BASIC in the C64, hence why you had to use pokes to do anything remotely interesting with the sound and graphics instead of high level calls like Sinclair BASIC.

        Still, having bad BASIC must have pushed a lot of people into learning machine code and doing proper programming.

        1. Frumious Bandersnatch

          you had to use pokes to do anything remotely interesting with the sound and graphics instead of high level calls like Sinclair BASIC

          But on the other hand, the manual that came with the C64 was pretty good and included lists of addresses to peek/poke for changing colours, using sprites and making music/sounds with the SID chip. There really wasn't a need for extraneous syntactic sugar within the BASIC interpreter when the peek/poke addresses were documented. The more complete "Commodore 64 Programmer's Reference Guide" even included schematics for the C64 itself along with a wealth of other technical info such as for accessing bank-switched RAM, a full memory map and even tables listing the frequencies in Hertz of standard musical notes and trig identities. It also had a pretty decent introduction to writing assembly on the 6510.

          That document probably ranks as being the best technical manual for any computer I've ever used, even to this day. They just don't write manuals like that any more, unfortunately. I've still got two copies of it floating around :)

  10. TRT Silver badge

    I used one a few times...

    but never had one of my own, but I'm not getting all dewy eyed over the memory of picking up a new game on a cassette from Mr Micro and rushing home with it, the trepidation and impatience of watching the loading screen... glory days,

  11. Richard Scratcher

    File? What file? I don't remember saving any files!

    I owned a Sinclair QL and its Microdrives were a real let down. The QL was very late in delivery and had a "dongle" attached to fix the issues that made it so late.

    For me, saving files to a Microdrive was a fingers-crossed affair and I would always verify that the file had been saved and then save it again to a second cartridge... or even a third.

    1. Anonymous Coward
      Anonymous Coward

      Re: File? What file? I don't remember saving any files!

      With such tiny tapes I can only imagine that alignment was a real pain.

      Cleaning the heads would help too.

      1. Frumious Bandersnatch

        Re: File? What file? I don't remember saving any files!

        With such tiny tapes I can only imagine that alignment was a real pain.

        At least they had the good sense to only store one track on the tape rather than go with the idea of basing it on 8-track (or similar) recording format. If alignment with just one head is a problem, imagine how bad it would have been with multiple tracks/heads.

    2. Irongut

      Re: File? What file? I don't remember saving any files!

      The QL didn't have a dongle, it had a KLUDGE.

      I can't remember if that was the official name for it or just what all the magazines called it at the time.

  12. Anonymous Coward
    Anonymous Coward

    I had one of those

    And the Logan book, which I studied quite carefully.

    The memories... the first thing I did when I bought a game on cassette was to dump it on a microdrive. That meant I had the tape as a backup and could enjoy the faster load times. One of the things where I burned a lot of time back then was with multi load games that came on cassette. With some work you could make them load the parts from the cartridge. Games that were unplayable because of the long pauses for loading stages became a different, way better, experience.

    I later repeated that trick with the diskette based Spectrum Plus made by Amstrad. Karnov was a fun game when the parts were quickly loaded from disk instead of from cassette, and I always wondered why they did not released a disk version in the first place. Games then were cheap enough to be affordable for a kid using pocket money, and at that point the challenge of breaking apart multi load games had lost its attractive. At the same time, my income increased enough to be willing to pay a bit more for a disk based game and save the hassle of disassembling and circumventing copy protections.

    On reliability, I perhaps was lucky, I think I lost two or three cartridges during the entire lifetime of the system.

    And I never had a chance to use the networking or RS232 interfaces, neither I know of anyone that did. Same with chaining more drive units, they were expensive enough to have just one, much less to even think of getting more.

    Oh, the fond memories. Thanks, Reg.

    1. Anonymous Coward
      Anonymous Coward

      Re: I had one of those

      I played with the networking a couple of times.

      Worked quite well really.

  13. Anonymous Coward
    Anonymous Coward

    there is no such thing as a novel idea / invention ,!

    this story say it all :

    There is no such thing as a novel /independent ideal or invention,

    - there are 7 billion people in this world - the possibility that some one else also have the *same* idea is more probable than one thinks/imagines !

    1. Khaptain Silver badge

      Re: there is no such thing as a novel idea / invention ,!

      That's not realy true, someone , somewhere definately had an orignal thought/idea that ran through his brain. Whether or not the idea was made publically available or patented is another problem.

      For example : I was considering the idea of capturing some pheasants ( Syrmaticus reevesii), attaching electrodes to their legs and trying to power up a smartphone for which an application has been written which helps the user to find new pheasants. A kind of reciprocal animal hunting application.

      "Similar" ideas might exist but the chances of someone having the exact same idea are probably far smaller that 1 in 7 Billion...... there might be some attaching of electrodes to "fruit" alternatives but that is not my intended goal or idea.

      I would definately consider this as being a novel idea and I am happy to take the credit for being the first person on this planet to think about it.....

      Unlesss of course your ideas are very generic . ie - "I want to invent a computing device" which today would not be an original idea.

  14. Bee Keeping Is Much More Fun

    The best...

    ...article I've read in a long time - Dale's - The Sinclair Story book is now going for £36 + on Amazon. I now regret selling this for 50p at a boot sale about 10 years ago.

  15. Lee D

    Never had a microdrive, but my dad bought my brother and I an Interface 2 with some of the ROM cartridges. Why they didn't just go that way in the first place, I'll never know. Instantaneous loading of games, literally plug in the ROM, turn on the machine, and you were in the game - so one of the first "game cartridge" consoles, really, and they could have made a killing by pushing that. Spoiled only by high price on the cartridges mainly due to the rarity.

    Still have it around somewhere, with the original ROM cartridges (Jet Pac, Hungry Horace, Planetoids, there were only about 2-3 other titles that ever came out on that format).

    Even had the NES "trick" of blowing on the cartridges to make them work, though they were much less susceptible to handling and dust problems because they had a red rubber "skirt" which covered the exposed PCB contacts on the cartridge edge, which were pushed aside by the Interface 2 ROM slot.

    If Sinclair hadn't spent the money on Microdrives but pushed to get the ROM prices down, or even make them EPROMs so people could use them to store their own programs, the gaming world would have been a very different place and they could have started to rival Nintendo almost immediately.

    1. Graham Dawson Silver badge

      Ok your story is nice, but I have to rant about this.

      "my brother and I" makes no sense in your sentence. It's an example of false grammatical correctness - you've learned the rule that "me and my" is incorrect and applied ot universally. "My and I" only applies when you are the actor. When another is acting on you, it is "me and my".

      The test is to take your brother out of the sentence.

      "my dad bought I an Interface 2"

      See the problem?

      You're right about eproms though. Imagine how different the world would be.

      1. Lee D

        Though I have been known as a grammatical Nazi at times, it's an internet forum and my intention was clear.

        That said, I often re-re-re-re-re-re-revise posts before I click submit, not for grammatical correction, but to rewrite the sentences to add bits (my memory is very odd and doesn't work properly). In this case "My brother and I" originally started the sentence before I later added the part about my dad actually doing the buying (I was just a sprog back then, and it seemed unfair to leave out that my dad actually paid the money for it, and people might think I was REALLY old if I don't).

        Looking at my post history, you'll see that I also have a history of breaking sentences into complete gibberish when I do this, by inserting an additional note into a sentence and forgetting to clean up around it or rewrite the tenses, etc.

        When something is unreadable due to poor grammar, I'm just as vehement as anyone else. But the pedantry applied when the intention of the sentence is clear really doesn't improve anyone's English. Actually, I use me and my a lot more often than anything else (Hell, I'm Cockney, and will even substitute 'me' for 'my' in conversation!), but I think you'll see that this is just an example of re-edit laziness rather than attempting to use grammar beyond my grasp.

        I could probably pick out errors in this post too (comma overuse, possibly?) but unless it stops anyone actually reading the post and understanding what it means, then I wouldn't bother to try and fix it.

      2. Gav

        Me right

        This error is second only in my list of annoyances to the polar opposite of people who say things like; "Me and <friend's name> went to the pub."

        Take out the "and <friend's name> and you're left with "Me went to the pub." They sound like a self-centred 4 year old, in which case they shouldn't be getting served at the pub.

        Just because I'm a Grammar Nazi doesn't mean I'm not right.

        1. NomNomNom

          Re: Me right

          "Just because I'm a Grammar Nazi doesn't mean I'm not right."

          Inevitably the Grammer Nazi will overextend themselves, fighting a grammar war on multiple fronts and eventually shooting themselves in the head in a bunker when it all falls apart.

          1. Anonymous Coward 15

            @NomNomNom Re: Me right

            >"Just because I'm a Grammar Nazi...

            >Inevitably the Grammer Nazi...

        2. sleepy

          Re: Me right

          English is an evolving language, and this case both forms are used, depending on the names of the people involved. Thus "Me and Tracy went to the pub" and "Elizabeth and I went to the pub" are both acceptable. But if the names were swapped, they would both be unacceptable.

          1. John Bailey

            Re: Me right

            Not to mention awkward, when Elisabeth and Tracy find out about each other.

      3. mgumn


        Have you been to the west country?

        My bristolian colleagues often construct sentences like "my dad bought I an Interface 2"

        1. Anonymous Coward
          Anonymous Coward

          Re: Bristol

          I may be wrong, but I believe that this is because the original version was "my dad bought oi...", and oi is not some comical Bristolian mispronunciation of "I", but an earlier English word meaning "me". I used to know a young woman from a farm in rural Somerset who spoke real Somerset, with its own vocabulary and grammatical differences, and it was a pleasure to listen to.

          Similar things happen in Yorkshire English where apparent mispronunciations are actually from Norse words.

          1. Anonymous Coward
            Anonymous Coward

            Re: Bristol

            In any case if its proper Bristollian it would be "my dad buys ..." - none of these fancy tenses here please.

        2. Anonymous Coward
          Anonymous Coward

          Jamaica Re: Bristol

          Rastafarian dad's may even have "bought I and I an interface 2"

      4. Codeus

        .....applied ot universally....

        Did you mean 'applied it universally' ?

        Glass houses, stones.... and I...

    2. Irongut

      I had an Interface 2 as well and it was a great peripheral and made much more sense to me than buying an Interface 1. But, there was a very good reasons why the ROM cartridges were no alternative to Microdrives - they only held 16K! That is why the only games that came out on cartridge were the older 16K Spectrum games that you mentioned.

      I had Jet Pack btw, great game. :)

  16. stu 4

    another excellent speccy article

    ideal reading over my morning coffee.

    I remember looking at these in boots/etc in 83/84 as a spotty 12yo (who'd just had his first speccy educational game published) with very envious eyes.

    never happened though - I ended up moving to an Amstrad 6128 - which seemed relatively spaceage at the time - real colour (it even told you what they all were on the top of the disk drive), AND a proper disk drive. It was like scifi had landed in my bedroom (even though my budget didn't extend to a monitor - so it was still plugged in to the 1978 hitachi tv.

    1. Anonymous Coward
      Anonymous Coward

      Re: another excellent speccy article

      But Amstrad didn't sell them without a monitor, even if you asked really nicely. In fact the PSU was built in to the monitor and the 6128 required 5v for the main board + 12v for the disc drive.

      I assume you had the MP3 modulator, which would have been the only way to get power + a UHF out. But I'm just interested how you got a 6128 without a monitor as Amstrad's policy was never to sell them separately.

  17. This post has been deleted by its author

  18. ukgnome
    Thumb Up

    Great article

    I never had a speccy, but it was always obvious to me that they had style and marketing speak over their competitors. Hmm reminds me of a fruit based firm.

    1. Dave 126 Silver badge

      Re: Great article

      My old man has never got on with his iPod- gets confused by connecting it to a PC- but he loves his Brennan JB7. He puts in a CD (of which he has hundreds) and three minutes later it spits it out, having ripped it to its internal HDD and compared it to its internal database for track titles. It's probably not of interest to Reg readers (some of you would use a RasPi and networked storage, I'm sure) but it really is a well thought out device for its intended market.

      He has recently discovered Spotify, but stupidly it only works in 'portrait mode' on his tablet.

  19. LinkOfHyrule
    Thumb Up

    Good article!

    Another good el-Reg exposé into old computer stuff! Ideal reading over my morning tea, not coffee! I am too young to know about stuff like this but its fun reading about it.

  20. Naughtyhorse

    The real sinclair story...

    A stupid idea, badly implemented and rushed to market.

    how i miss the 80's

    1. Anonymous Coward
      Anonymous Coward

      Re: The real sinclair story...

      Sinclair were massively obsessed with price. Everything they did seemed to be very optimal to the point of being border-line usable at times. Just think of the dead flesh rubber keyboard or the earlier membrane jobbies.

      The Microdrive is another example of how they decided to produce a simple, cheap design rather than look at ways of sourcing cheaper parts.

      Commodore for instance lowered their costs on devices by purchasing MOS and vertically integrating, this is just another example of how businesses in the US behave differently to the UK at times.

      Sinclair was doing the wrong sort of custom work, he should have been using off the shelf storage formats (like he'd done with the speccy using normal tape recorders) and actually saved the custom work for the important stuff like graphics and sound (which were both massively dire on the speccy compared with the C64).

      1. ThomH

        Re: The real sinclair story... (@AC)

        The difference between the C64 and Spectrum graphics are decent hardwired graphics semantics with a weak CPU versus a cheap-to-manipulate frame buffer with limited colour resolution and a speedy CPU. Trying to reduce it to one being definitively better than the other isn't really constructive. Both have been pushed much further now by enthusiasts without budget limits but for every Creatures there's a Knight Lore, for every Revs there's a Hard Drivin'.

        Given that in 1984 (when I could most readily find prices via Google) a C64 cost £195.95 and Spectrum was £129, I don't think it's fair to make the blanket statement that Sir Clive's lot were optimising incorrectly.

        1. Naughtyhorse

          Re: The real sinclair story... (@AC)

          That's a fair point considering this instance in isolation, but taken on the whole 'for a ha'porth of tar..' should have been the sinclair family motto. He constantly cut corners, and most of the time it bit him (and his long suffering punters) on the arse.

          Makes me chuckle to see comparisons with jobs/apple on this list.

          In clive's case 'Don't you love it when things just work' maps to 'fuck me! it works! amazing!!... nope it's gone again'

  21. rich_a

    Fascinating story

    I really enjoyed reading this, although it could have done with being proofread.....

    I used to love the rigmarole that went with buying QL games. When you tried to run them from the microdrive that came in the box, it would force you to make a backup to an empty microdrive (another couple of quid to Sir Clive!) and then you'd need to boot from your copy and keep the original MD in the second drive to pass the copy protection they'd put on the game. It seemed that even the publishers knew how fragile they were!

    I worked with an ex-ICL chap who insisted that they almost deconstructed and reconstructed the microdrives and drives for the OPD system. I'd love to have known more about that!

    Also have great memories with the AmSoft 3" disk format. Used to be impossible to find them for a reasonable price - used to regularly raid the bargain bin at the local computer shop and buy unwanted CPC/+3 games as they would be cheaper than buying blank media!

    1. /dev/null

      Re: Fascinating story

      One of my most satisfying bits of hackery I did on my QL was reducing the number of cartridges required to load The Pawn from three (two "working copy" carts plus one original for copy protection) to one - I worked out I could squeeze the the contents of two cartridges onto one, which I formatted with the same magic ID code as the original cart using some Microdrive "utility" software. Playing the game was almost as much fun...

      Must power up my QL again and see if the Microdrives still work - they did about 4 years ago...

    2. Anonymous Coward
      Anonymous Coward

      Re: Fascinating story

      A quick scan of a 1988 issue of ACU reveals 3" discs retailing for £2.50 each or £23 for 10. This tallies with my memory of them being about 3 quid each.

      Part of the cost was the fact they were manufactured like brick outhouses. They were designed to be tough enough to be able to be sent through the Japanese postal system with no protection other than their case. I have one on my desk and they are tough beasties. Had loads and I can say I never had one fall apart, but I have had 3.5 inch discs have shutter mechanisms that have gone wrong or got damaged.

  22. Fihart

    Sinclair, what was that all about ?

    Not long after the QL was announced (though it notoriously actually came out much later) there were already fairly affordable computers like the Sirius and, later, the Apricot.

    Unlike the QL, these actually, seemed usable in business due to a decent keyboard, software like Wordstar and floppy drives -- the Apricot even had Sony 3.5 inch 720k drives which were, as promised, entirely reliable and could be fed for as little as £2 a disk.

    When the Amstrad PCW materialised at the Sinclair price point , it used small floppies. Aside from hobbyists, that seemed like the end of Sinclair computers to me.

    My experience of Sinclair products was, anyway, mixed. The small Sinclair hifi amp was not known for reliability and according to legend the hifi kits included Plessey modules repackaged with a mysteriously 'uprated' output. Any "breakthrough" in storage based on what looks like 8-track cartridges, but shrunk, seems a bit batty at this remove.

    1. Anonymous Coward

      Re: Sinclair, what was that all about ?

      RE Sinclair reliability. First thing Sugar did was to move production out to the Far East. Costs of using the Timex factory in Scotland were very high due to very high faulty return rates and stock going "missing". Rumour has it everyone in Dundee had a Spectrum, mostly bought from a man in a pub.

      A story is told by an Amstrad engineer that when they got the circuit diagrams through from Sinclair, the Spectrum was so over complicated that they were scratching their heads about how it actually worked. When they figured it out they integrated everything down into a few IC's vastly reducing the component count.

      Here's the 128k Spectrum circuit boards. The Sinclair version is at the top and the rest are as Amstrad developed them. Look how they reduce the component count.

      1. John Deeb

        Re: Sinclair, what was that all about ?

        Mr C Hill "The Sinclair version is at the top and the rest are as Amstrad developed them. Look how they reduce the component count."

        Not a likely account. If you look more closely the component count could be said to have been increased with Armstrad, barring perhaps the availability of cheaper higher density RAM in those days (and decrease of discrete IC's). If you'd compare the Sinclair motherboard with most of the competition at the time, it would be Sinclair having the most reduction done in space - or just leaving out "luxury". Including decent capacitors!

        What is more likely is the story about the complications. To cut corners some odd constructions could be found in the circuit diagram. But in my experience they were all cost-saving at a time the price per component was high enough to justify those added twists.

        1. Anonymous Coward
          Anonymous Coward

          Re: Sinclair, what was that all about ?

          I disagree, having the advantage of having actually spoken to an engineer who worked at Amstrad at the time.

          The first +2 was rushed through as Amstrad has to get stocks in ready for Christmas. They didn't do much re-engineering at that stage. It was a rush job, so rushed in fact that in his book Sugar reveals that he was already committed to the tooling required before he had even signed on the dotted line. In fact the book also reveals that before Amstrad had the plans, they went down to Dixons and literally bought a 128k Spectrum to dissect. They had less than 6 months to get the machines into the shops which is less time than you'd think when you factor in production lead times and how long they'd be on the boat.

          The real changes came with the +3 where you can easily see number of components has dropped significantly. They've also managed to engineer out the ridiculous heatsink.

    2. Ivan Headache

      Re: Sinclair, what was that all about ?

      I think you are being a bit harsh on Sinclair. The QL was actually a very good computer - once you had added external drives (of which there were several tto choose from). Also it was expandable, several companies (most notably Miracle Systems) made sub-assembles that would plug into the expansion port on the left-hand end.

      Mine had a Miracle Systems Gold card that upped my RAM to 2MB and gave me an interface to 2 Mitsubishi ED floppy drives (2.88MB each).

      I had an Epson Laser printer (EPL something or other) that cost more than the entire QL set-up!

      With that (and later the Cambridge Z88 portable) I ran my part-time photographic business, learned database development and generally got on the road to becoming a trainer and support bod.

      With regard to their amplifiers, I still have a Sinclair System 2000 amp (although I don't use it) but I would really like a Neoteric 60 amp (if I could find one).

    3. Andus McCoatover

      Re: Sinclair, what was that all about ?

      Anybody willing to help my dementia here?

      I seem to remember buying a chip, with an aluminium 'armadillo' heatsink stuck on its back (It actally worked very well, but got extremely hot!). IIRC, I stuck it on a board, with the tracks carved out by a scalpel I "purloined" from my mother - who was a nurse at the time. Holes 'drilled' by knocking a nail through carefully marked holes. (Oh, Veroboard! Where would we be without you!)

      Put a 'skeleton' gramaphone into a wooden chess-box I had, connected to the speaker of a defunct wooden wireless we had. It worked. Powered by a 6V? motorbike battery I found on the local rubbish tip.

      Envy of my friends. Think I was about 13 at the time. Would that really be 44 years ago?

      Was it a Sinclair? I bought quite a few bits'n'bobs from Sinclair in my yoof, starting withe the MK14.

      1. drgeoff

        Re: Sinclair, what was that all about ?

        The chip with the armadillo heatsink was the Sinclair Super IC12 power amp. It was actually a remarked Texas Instruments device. I soldered all 5 of mine into matching PCBs also supplied by Sinclair. I cannot recall if the PCBs were an extra purchase or bundled with the chip.

        The earlier IC10 audio power amp, with metal heatsink bar running through it, was a rebadged Plessey device.

    4. John Brown (no body) Silver badge
      Thumb Down

      Re: Sinclair, what was that all about ?

      "Apricot even had Sony 3.5 inch 720k drives which were, as promised, entirely reliable"

      No. Just no!

      We had 10 Apricot F1 computers. The likelihood of any one drive being able read a disk formatted in another drive was depressingly low. No problem with the supplied, mass duplicated discs but locally formatted blanks was another story. Our solution was to work out which people needed to swap data most often and "pair up" the computers to minimise read errors.

      On the other hand, if you needed to format a lot of discs at once, placing up to four F1s side by side and using one infra red linked keyboard to run all four computers was quite cool!

      1. Fihart

        Re: Sinclair, what was that all about ?

        @ John Brown

        The Apricot F1 was an unloved cheap bastard offspring. The Apricot PC and hard drive Xi were pretty good. The two Xi models I have used could occasionally trip up and fill the screen with a particular weird character. The cry would go up: "the screen's full of penguins again" and it would be time to reboot.

        Kept my Apricot PC for nearly 8 years, only replacing the keyboard and adding extra memory and a modem (a rarity then). This was only the second computer I'd used and the first I owned -- I had to send away for a Wiley book about DOS and learn to program the dot matrix printer I'd added but the Apricot was otherwise a complete working machine rather than the desk full of boxes and cables that Apple and BBC offered.

  23. Lxbr

    Remember ZX Net?

    As well as the microdrive interface, the Interface 1 also had a 'proper' RS232 socket and a ZX Net socket for Sinclair's proprietary Spectrum (and later QL) LAN setup. Me & my Dad once networked about 10 Speccies together, mostly to see if we could - there was hardly any software available that actually used ZX Net. I believe the limit was 64 nodes on the LAN, probably someone once did that many for a laugh.

  24. Robert Forsyth

    What happened to the innovation of the 80's

    Did Thatcher's policies suck the money out of technology to buying houses and city fat cats' Porsche? Discuss.

    1. Christian Berger

      Re: What happened to the innovation of the 80's

      Probably, although even by 1980s standards this wasn't particularly innovative. Back then there were already systems like the LINC/DEC-tape, which provided random access with ridiculously simple drives. Those drives didn't even have a capstan. The system was designed so tape speeds were largely irrelevant after it was formated at a controlled one.

    2. Anonymous Coward
      Anonymous Coward

      Re: What happened to the innovation of the 80's

      Sadly I think the scope for such a large range of products which enabled all this innovation has gone. Computer means PC or perhaps Mac now, games machine means PS3, Xbox or perhaps Wii etc. Suppose RaspberryPi is a sort of throw back to that era. Similarily games now have teams of 100s working on them - back in the 80s a teenager could write a game in their bedroom and get it published (I did) ... again, I suppose "apps" are an area where that may just about be possible again - though my latest game app - RealRacing - is clearly way way beyond the small scale innovation level. Even in hardware everything is become increasingly commoditised - IP providers like ARM may be a great success but it means that to some extent they handle all the innovation and the rest of us just use digital allen keys to bolt flat pack designs together.

    3. JohnG

      Re: What happened to the innovation of the 80's

      We were busy paying back a huge loan to the IMF and living under the austerity demanded by the IMF as a prerequisite for that loan, following the disastrous Labour and Lib/Lab Pact governments of the 1970s. Many seem to have forgotten that inflation peaked at 26% in Harry Wilson's second term and the resultant pay demands of 30 - 40% ultimately lead to the IMF loan and the Winter of Discontent.

    4. Fihart

      Re: What happened to the innovation of the 80's

      In all industries the early days are marked by lots of little firms doing things differently but, in the end, the market and economies of scale whittle these, away leaving major brands (which often then crash ingloriously).

      The British car industry. Riley, Morris, Austin, Wolsley -- Standard, Triumph, Alvis -- Hillman, Humber, Singer, Talbot, Sunbeam. All were absorbed into three majors, then two, then one, then none. And that's not counting the tens of brands which disappeared before those mergers -- Lea Francis, Armstrong Siddley, Jowett, Lanchester.

  25. Rob Quinn

    I still have a couple of Microdrive cassettes at home that I was given by a family member in a bin bag full of speccy games, thing was I never had the drive to run them, did have the interface 2 with the rom catridges which was so much faster than loading off an audio cassette.

  26. Guy Geens
    Thumb Up

    Great memories

    I never owned a Microdrive, but I knew people who did.

    Each time you formatted a cartridge, it would report a slightly different number of sectors. So they would format a few times in a row until they got a slightly higher capacity.

    Thanks for mentioning the Wafadrive.

  27. banjomike
    Thumb Up

    Don't forget Exatron

    Exatron invented the "Stringy Floppy" continuous tape in 1979. I used one on a TRS-80. Very nice too. And reliable unlike the Sinclair thing.

    1. Dick
      Thumb Up

      Re: Don't forget Exatron

      Yep, I had one too, it worked very well.

  28. deshepherd

    BBC Micro Hobbit drive

    I was in the BBC Micro camp and remember seeing an advert in one of the computer mags for a new "floppy tape drive" called "the Hobbit" which was "faster than tape, cheaper than disk". Wasn't a continuous loop but wsa a high speed "cassette" which I think had "random access". Anyway, as it was ~1/3rd price of a floppy drive I decided I'd get one and persuade my parents to go via a shop somewhere in North London on our way somewhere. Went into the shop and said that I wanted to buy a Hobbit drive and the person in the shop basically replied "no you don't - they're not really worth the money - you want to save up the extra to get a floppy drive"!

    A bit later I did get a floppy drive ... drove myself to N London that time to find this company that was advertising cheap floppy drives in the mags ... it was called "Viglen"! Got there to discover it was basically a company that had been making plastic boxes that seemed to have discovered that they could get a lot more money for their plastic boxes if they put a floppy disk drive in them.

    1. Tim Walker

      Re: BBC Micro Hobbit drive

      I owned a Spectrum (48K) myself (though if I'd had a snowball's-chance-in-Death-Valley of affording a Beeb, I'd have jumped at it), but in 1983 my primary school held a series of fundraising events to buy a BBC Model B with (intake of awed breath) a 5.25" floppy disk drive. Oh, how I wanted one... from waiting 3-4 minutes to load a Speccy game off cassette, to just a few seconds on the Beeb - "this is the future", my school-age self thought...

      Back on-topic: no, I never owned a Microdrive (too pricey), but I could swear I remember seeing one in WHSmith - still can't believe they ever sold computers - and more recently, in the computer museum in Swindon.

      Oh, and after all these years, I finally own a Model B... Raspberry Pi. I'll settle for that :-)

      (where's the icon for "misty-eyed middle-aged nostalgic", Reg?)

  29. Neill Mitchell

    More reliable microdrives

    The microdrive to have for the Speccy are the ones with a little raised strip running front to back on the left in front of the pinch wheel. It aligns the cartridge better to the rollers and these drives are more reliable than the older ones without it.

    When I went through a short nostalgia phase of buying microdrives a few years back, I'd always peer down the slot or ask the ebay seller to check the drive was one with the bump. Speccy nerd eh ;)

    The last QL's also had more reliable drives made by a 3rd party. These often still run without problems today and so are the more sought after QL's. The drive manufacturer? An unheard of company at the time called Samsung :)

  30. Dangermouse 1

    Have to answer this: "the amazing SAM Coupe - the last UK home computer until the Raspberry Pi."

    SAM Coupe - 1992. Acorn RiscPC - 1994. Castle Iyonix 2002.

    1. Chika

      *Sigh* I remember seeing an Iyonix on display at a local UG around the time it was first being released. Was very impressed. Was very broke. Wasn't working. Didn't get one as a result.


    2. Anonymous Coward
      Anonymous Coward

      Good point - let me edit my previous post to "one of the last".

  31. andy gibson

    Joining drives

    It was only the first drive that connected to the IF1 with a ribbon cable. Subsequent drives were connected by a connector like this:

    and a plastic plate on the base of the microdrive was used to secure the drives together.

    Still got mine, still working, along with the +D and various drives.

  32. Enrico Vanni

    Strathclyde University and the QL

    Anyone who did Computing Science courses at Strathclyde Uni. in the late 80's will remember the headache that was the microdrive cartridge very well. I don't know the exact nature of the deal, but it seemed that all the unsold stock of Sinclair QLs ended up at the University, with several labs stocked out with them, plus hundreds more than students could 'borrow' from the library for a term at a time for a small deposit.

    Programming assignments had to be submitted fortnightly, and there was always the nervous moment when you popped your cartridge into the lab machine and the damn file wouldn't load because of the inconsistency in the read-head alignment of the machines, or worse your cartridge tape had stretched beyond its usefulness and the program you'd been working on for days was corrupt. We all learned the importance of backups the hard way!

    Eventually the Uni. gave up on the microdrives and equipped all the lab QL's with 3.5" floppy drives, before retiring the whole lot a couple of years later.

  33. vanpeebles

    Sinclair QL

    Interesting article. Sinclair was approached by floppy makers to use their drive in the QL but stuck with the microdrive. Who knows what might have been but it's still an enjoyable machine with a great community.

  34. A Non e-mouse Silver badge

    Interface 1 & ROM compatability.

    The article mentions that the Interface 1 had fixes for bugs in the Spectrum ROM. I seem to remember this caused problems with some programs. I definitely remember seeing code samples in Speccy mags about detecting if an Interface 1 was present so you could take account of the ROM changes.

  35. A Non e-mouse Silver badge
    Thumb Up

    Mix 'n' Match

    As a child, I managed to persuade my parents to let me spend my savings on an Interface 1 & MicroDrive for our Speccy. For the first six months or so, the Interface 1, MicroDrive & Spectrum spent much time to-ing and fro-ing to Sinclair.

    It seems there was a magic combination of MicroDrive, Interface 1 & Spectrum that worked. It took me & my parents months to get a working combination.

    Ah, the memories.....

    1. Anonymous Coward
      Anonymous Coward

      Re: Mix 'n' Match

      what speed does your telephone modem connect at?

  36. Kubla Cant

    Stringy or skinny? You decide.

    The article mentions the Exatron "stringy floppy", but by the end of the paragraph it seems to have become a "skinny floppy". I think you're confusing your drive with your coffee.

    I remember using some kind of cassette-that-thinks-it's-a-disk on a DEC computer - probably an early VAX. I think we had to boot VMS from these things to perform a standalone backup.

    The problem was that the tape's emulation of a disk drive was so convincing that the computer was fooled into thinking it really did random access. The thing was formatted with Files-11, a filesystem more appropriate to disks. My impression is that it would read a few sectors, then discover that the next sector was at the other end of the tape. Cue a long wait, with much clicking, grinding and whizzing.

    1. David Flanders

      Re: Stringy or skinny? You decide.

      The DEC tape was the TU58, I remember booting a VAX 11/750 off it and it was used in the cluster hard drive controllers.

      You're right about the long wait and the clicking, grinding and whizzing though.

    2. banjomike

      Re: Stringy or skinny? You decide.

      Exatron's toy was definitely a "stringy floppy". It came with nifty software that pretended to be a disk drive (random reads & writes and such). very nice to use.

  37. Clive Galway

    The microdrive wasn't that bad. I used one for ages and it did me proud.

    Combined with the Romantic Robot Multiface One it was a godsend - load up a game, get past the annoying copy protection (ELITE with LensLok I am looking firmly at YOU!) then dump the memory to MD or Floppy and life was all good.

    By the time I got my +3 though with 3" disks it got consigned to the bin

  38. Murphy's Lawyer

    Happy times with a Microdrive

    I only picked up a Spectrum in 1984, but it was a bumper "sale pack" with an Interface 1 and two Microdrives

    Two things made it incredibly useful: a piece of third party software "guaranteed" to format a cartridge to 96k, and Romantic Robot's Multiface 1, which dumped the Spectrum RAM to Microdrive and let you restore it later. For games with no save point, or awful copy protection like Elite's "Lenslok", or just going back a couple of days in "Doomdark's Revenge", it was almost indispensable.

    When I finally got rid of the Spectrum, I had over 50 cartridges, and had only two die on me. For all that it was a kludge, the Microdrive served me well.

    1. mickey mouse the fith

      Re: Happy times with a Microdrive

      "awful copy protection like Elite's "Lenslok""

      I was one of the unfortunates who bought ace by cascade games from a batch packaged with the wrong lenslok. Sometimes it took an hour of loading, trying 3 times, rebooting until you got past the bloody thing. Im pretty sure it was mostly chance as well as most times the code was so garbled that guessing was the only option. I seem to remember a pretty strict timer before it rebooted itself as well, just to angry up the blood that little bit more. Like you, i ended up using a backup device to save the bugger from ram, thus ending the misery.

      And of course, after this debacle, companies learnt from this lesson and never again released games with drm schemes that made them inconvienient to play or completely unplayable for the paying consumer.*

      *may not be strictly accurate.

  39. Anonymous Coward
    Anonymous Coward

    Does anybody remember the some cool hardware...

    - which let me use a real 3.5" floppy drive and could dump the memory contents to it at the press of a button, for virtually instantaneous loading of all my games at the press of a button - was it called 'snapshot'? - advertised in some of the mags at the time.

    I didn't dream it - I've still got it in my 'legacy' spares box

    1. Anonymous Coward
      Anonymous Coward

      Re: Does anybody remember the some cool hardware...

      Do you mean the +D by MGT? Your description fits the bill.

      The same company produced the ill fated Sam Coupe. Now there is a story and a half!

    2. Anonymous Coward
      Anonymous Coward

      Re: Does anybody remember the some cool hardware...

      May have been a Opus Discovery 3 1/2 FDD. I had the microdrives initially, then moved to the Opus. It had a Kempston Joystick port out as well as powereding the spectrum from its own power source via the interface slot. Again, used with the Multiface 1... brilliant.

  40. Anonymous Coward
    Anonymous Coward

    Rose tinted hindsight?

    All these articles on 80's computers begs the question, was computing more fun then, or has my memory donned rose tinted specs?

    I loved my Beeb, it outlasted Atari ST and my first IBM clone, I've lost count of the number of Speccys I fixed, C64s as well (though melted power supplies was their biggest problem), I've had a QL and an Oric and they were all fun in some way shape or form.

    Modern reliability is nice, admitted, but somehow modern computing seems boring in comparison to the mid 80's to early 90's. Maybe that's why the Raspberry Pi has taken off?

    1. Charles Manning

      The past is always rose tinted

      I hated my time in the army, bu I can look back with some fondness 30 years on.

      Similarly it is nostalgic to think of the excitement and heroics of working with punch cards, limited memory and whacky C compilers that would crash if you deleted a magic comment from a source file.

      But really, the world is a better place now, Our software is far more robust, source control stores code far better than boxes of cards, and the Good Old Days actually sucked badly.

  41. andy gibson

    21st cenutury technology on 20th century kit

    The good thing is though, if you've still got your original kit you can still do fun things with them, such as all these CF and SD card adapters and virtual disks. Having a 256Mb SD card in my Beeb on a board that cost less than a tenner to make and having all those free disk images from the 'net on there is wonderful.

  42. John Moppett

    What about the offspring?

    I think that mention should be made of the offspring of this project, the ICL One Per Desk aka BT Tonto. Basically AFAIR a QL built into an early attempt at en executiev workstation. I used on when I was in BT Marketing, it incorporated a telephone and modem, with two lines. Apart from the normal functions of word processin et al I was able to interrogate a distant mainframe running RAMIS Reporter to obtain the relevant stats.

  43. Simon Harris

    Infinite Loop.

    If the Microdrive cartridges were on an infinite loop, does that mean that Apple were inspired by copied Sinclair with their choice of headquarters address?

  44. Levente Szileszky
    Thumb Up


    ...article, thanks. Spectrum was my first computer and anytime I see a pic of it my heartrate still goes up, even 30 years later. :)

  45. Curator


    The other machine that used microdrives was the ICL OPD (One Per Desk), a collaborative project between ICL, Sinclair Research and British Telecom

    Simon Webb

    Museum of Computing

  46. Chris Walsh
    Thumb Up

    I own three Microdrives. Two still work! :-)

  47. Irongut

    The Complete Spectrum Rom Disassembly

    That book was my bible for years.

    << A beer for Ian Logan.

  48. Slap

    I had one

    I had one, and despite it's flaws it was truly revolutionary compared to waiting 5 mins for data (read data as games) to load.

    Of course the afformentioned games didn't come on microdrive so with the little Z80 assembler I had I managed to hack a way of loading a game in while avoiding the microdrive memory map, dumping that back to microdrive and then write a small loader program for each game that would load and shift everything to the right memory locations after everything had loaded. I even used the memory area reserved for the video as a buffer for some games - if you ever wanted to see attribute screwup then that was a prime example.

    I think fondly of my microdrive. It had it's problems, but it was also lightning fast as far as I was concerned.

    Ahh those were the days

  49. Frumious Bandersnatch

    This happened to me(*)

    I'd built a crude mouse and circuitry to hook it up the the RS-232 interface. Then it took me weeks to write the mouse driver interface, saving it to the Microdrive. Alas the tape failed...

    Flappity Floppity Flip

    The mouse on the Mobius strip

    The strip revolved, the mouse dissolved

    in a chronodimensional skip!

    (*) well, not really; I just wanted to post this rhyme.

  50. David Glasgow

    Wafa drive

    .... Still got mine somewhere.... And talk about recovering ancient data, the sound of it came back to me reading this article. Sort of 'shuffa-shuffa-shuffa chuck-chuck"

    Oh yeah! An my GF at the time insisted on pronouncing it "waffer" drive.

    Not just tape that still stores ancient crap eh? Brain 3.7.2 -

  51. Alan Firminger

    Microdrive technology

    The article has a photograph of a spooled infinite loop and later describes this. My Microdrive was different. I describe my experience of the two methods of running a continuous loop to provide a bit of history.

    The spool :

    In 1947 I met continuous display from 16 mm film. A unit was provided that mounted on the projector. This pulled the film from the inside of a coil and fed the film back to the outside of the coil. The axis of the coil was vertical, the film edge rested on rollers so it circulated without much friction. The theory was that pulling the film out from the inside caused little or no friction as the movement was always away from the neighbouring surface. It worked almost perfectly. At an exhibition a film would run for a total of say 50 hours, and be pretty horrible at the end.

    The esses :

    In 1970 I met more continuous loop of film in microfilm duplication. This threw film into a chamber that contained it and drew film out from the bottom of the chamber. Within the chamber the film forms itself into a stack of esses. We would run a loop of several hundred feet at 120 feet per minute. Of course there was degradation, but not much. Silver emulsion survived several hundred passes, tougher materials were available for intermediates. At computer fairs there were big versions of this on display handling wide mag tape to drive the demos.

    In 1984 I found Microdrives would fail after ten accesses, reported way above.

    I broke open a carttridge and discovered that the method of recycling the loop was the esses but horizontal. The tape rested on its edge. I conjecture that this was the original design and the spool described in the article was a later version to provide a useable product. Several contributors above speak well of the Microdrive, perhaps their cartridges were version 2 .

    1. Alan Firminger

      Re: Microdrive technology

      I have searched to find references to continuous loop technology. My best result is the first couple of lines from the reference below. Interesting, but the esses have disappeared.,or.r_qf.&bvm=bv.43287494,d.d2k&fp=6cb2b1d09bc8520a&biw=1366&bih=680&

  52. Dig

    I actually have a microdrive cartridge in my coat pocket right now.

    Its a re-purposed Psion Quill cartridge that I ought a job lot of when Dixons were clearing the stock. I have a bunch of assembly macro code on them.

    I first bought the Wafadrive for the Spectrum as I liked the idea of the extra ports and cheaper cartridges. Got it home and it didn't work; apparently not compatible with version 3 Spectrums, so I went back and bought the microdrives and was amazed at the near instant loading of Ant Attack a fiendishly difficult game to learn to play at the time.

    The challenge was of course to spend hours loading programs of cassette to convert to microdrive. Often having to split the program and move sections around using the screen as spare memory as the copy protection methods of the original program would load over every spare byte of memory including the microdrive extensions to the spectrum code.

    I upgaded to a QL later and and i think I managed to get the two to talk over the interface one network and inbuilt QL network but I seem to remember they never really played well together.

    Oh the memories they were great days, if only the QL didn't have possibly the worst screen memory layout in the world ever which made the under powered, yet beautiful to code, 68008 processor a hard time to do anything grahically entertaining.

  53. drgeoff

    Microdrives never contained EPROMs (or ROMs).

    The article incorrectly states that the first 1000 or so microdrives had EPROMs. They only had one IC in them and it wasn't a ROM or EPROM. The Interface 1 had a ROM (8 Kbyte?) and I have previously heard that early units had EPROMs rather than masked ROMs.

  54. J.G.Harston Silver badge

    "..exclusive to Sinclair..."

    and that was the problem. With disks you can transfer data to and from other systems, with microdrives your data is locked into a pile of decaying plastic.

  55. heynownow

    Speed benefits when compared to tapes?

    I was a kid in Calcutta, India growing up with a Sinclair ZX Spectrum, and I could not get my well meaning father to invest in a microdrive, after he had already plonked some hard earned rupees on a "Compluter friendly" casette recorder, where you could vary the speed of the playback motor, to load programs slightly faster, provided the reading head and the capstan were clean. Can anyone tell me the loading time speed benefits of the micro-drive vis-a-vis std data cassettes in loading up say "Daley Thompson's Decathlon" or "Horace goes Skiing", which btw we all copied from each other using analog tape to tape.

    1. /dev/null

      Re: Speed benefits when compared to tapes?

      Well, it took 7 seconds for a Microdrive cartridge tape loop to complete one pass, so loading a game from Microdrive shouldn't take much longer than that (unless it was a dodgy cartridge and some sectors needed more than one attempt to read). A lot faster than cassette, and probably quite comparable to a floppy disk.

  56. Frank Leonhardt

    Not revolutionary at all.

    I didn't see anything revolutionary about the Microdrive, and I don't think anyone else in the comptuer world did at the time. There were several similar products on the market years before the ZX-80 even existed - such as the Exetron Stringy Floppy. Sinclair didn't invent the printer either; the ZX Printer was a very small, low cost and completely rubbish version of what came before. They did the same with the Microdrive; small, cheap and rubbish yet it seems to have aquired mythical status with those of a certain age. Other tape loop drives worked really well, but by about 1981 they lost any price advantage they once had to cheaper, smaller (5.25") and higher capacity floppy disk units, and the access times of tape loop could not complete.

  57. Ken 16 Silver badge


    I've still got a small box of micro drives for mine.

    Can't remember them ever working...

  58. Bsquared

    I really struggle to get my head around how the Microdrive infinite tape loop actually WORKED. So Alan Firminger's post above was fascinating. I still haven't quite grasped how the inside of the tape loop lets you draw the tape out without friction. Anyone got a link to a nice diagram?

    Mine was pretty damn reliable (and I too remember the joy of having Elite load in 7s without sodding Lenslok). So perhaps I had a v2 also.

  59. Nosher

    An actual 8-track floppy/tape implementation

    1977's Compucolor 8001 had an /actual/ 8-track cartridge tape system (which they called "Floppy Tape Memory") available for it. It was capable of storing 1MB (that was a lot of storage back then) which could be read at 4800baud.

  60. Oooooh mein handy!

    Go HORACE Go !!!

    After reading this article I tried hard to think back to my speccy+ when I was about twelve (oh how I loved my speccy!) but I cant remember the Microdrive.

    After reading the comments I wondered if anyone remembers the little cartridge type things that plugged into the slot on top of the interface. I think they were called Rom Packs and I only ever had one which was a game called Jet Pac (developed by Ultimate/Rare I think). It only took about one or two seconds to load and I loved it. No having to wait 5 mins while a tape loads only to end with a ' R tape loading error'.

    No matter how hard I tried though I could never manage to find any more 'Rom Packs' in the shops and although I don't remember how much they cost, I wonder how things would of turned out if Sinclair had pushed that side of technology more than tape or Microdrive?

    1. This post has been deleted by its author

    2. mickey mouse the fith

      Re: Go HORACE Go !!!

      They sold the complete range of little game cartridges in my local wh smiths back in the day. As they didnt ever stock the interface 2, i dont think they sold many.

      There were only ever 10 produced for retail sale, space raiders, chess, planetoids, hungry horace, backgammon, horace and the spiders, jetpac, pssst, tranz am and cookie. There was also a test cartridge for service centres and a few prototype parker brothers games that were never released.

      Thats actually a pretty good lineup, esp. jetpac, space raiders and pssst, which are still fun to play today.

      I seem to remember them being quite expensive compared to the pocket money friendly tape games, which, coupled with the 16k memory limit and the need for an add on interface unit to play them probably doomed them at retail.

  61. Sam Therapy

    I never bought a Microdrive

    A friend had a couple of 'em and used to back them up to his Sony Betamax tapes. The drives themselves were really twitchy, though; whenever his wife switched on the washing machine, they'd go bugfuck. Seeing him frantically scrabbling to unplug the Speccy, take out the cart and try to retrieve the tape was enough to convince me to stick to cassettes.

    Then I got my first Amiga but that's another story.

  62. EVEster

    Fun Times

    I had the pleasure of working for Sinclair Research for almost two years in the 80's firstly commisioning technical software for the QL, then programming on the last Sinclair version of the Spectrum which introduced a screen editor to replace the single key press function entry (ZX128).

    This article kicked into action some memory neurons...

    I had successfully used the Interface 1 and microdrives on a Spectrum for games development, compiling on a Cromenco CP/M machine and then downloading images onto the Spectrum over the RS232 i/f onto the Spectrum, saving the images off to microdrive. Testing and reloading images from microdrive worked a treat...far better than tape or serial download.

    The later version of Spectrum Microdrives worked reasonably well - the real problem for the QL was the capacity/speed increase from 85K to ~110K combined with the lack of a cassette tape interface. This meant that all programs had to be supplied on Microdrive, with the problem that a program written on Microdrive A had a high chance of failing to load on the customers Microdrive B. This was eventually solved but way to late for commercial success.

    The really sad thing about the QL was that the software, operating system and Basic were ground breaking for the time but the hardware configuration decisions just let the system down.

    Changing the tone...I remember the first action of the engineers on receiving a trial One-per-desk was to make it swear at them.

    The really annoying thing was that before the Amstrad sellout, Sinclair engineering developed a product called Tyche, QL with more memory and integrated floppy disk which would have been a fine competitor to the Atari ST and BBC Micro but never saw the light of day.

    -- Andrew

  63. fattybacon

    Teesside Poly pimped the QL

    In 1985 every student on the HND Information Systems at Teesside Poly were loaned a QL and matching 14" crt monitor for the two year course. I still have the welts on my hands from carrying them the to the train station.

    Assignments were to be brought in on the damn microdrive tapes. If I'd have been a bit more savvy I would have realised that I didn't have to do the assignments, just blame the tapes. I ended up doing the assignments and invariably losing them.

    Our machine code lecturer was a big cheese in the 68008 world, he worked part time for Motorola (more likely a research contract). Seems odd to have someone genuinely good at such a 'ahem' 2nd tier 'university'. Maybe he was a degenerate.

  64. Anonymous Coward
    Anonymous Coward

    MGT disciple +d Ingo Truppel MB-02+ DMA 3½" hi/extended density?

    no mention of the MGT disciple +D or the MB-02+ from Ingo Truppel with hi density and DMA

    1.8MB on a 3½"floppy

    what happens when someone adapts an IDE to compact flash and twin SD to fit inside the microdrive?

    rom reprogram?

    amazing it didn't have 16kb of ram in the rom area - ideal for bbc basic etc

    1. Anonymous Coward
      Anonymous Coward

      Re: MGT disciple +d Ingo Truppel MB-02+ DMA 3½" hi/extended density?

      Oh no - the comments have been Jowetted!

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