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25th Anniversary of the Sinclair ZX Spectrum 310

Alioth writes "Twenty five years ago today, Sinclair Research launched Britain's most popular home computer of the 1980s — the Sinclair ZX Spectrum. Costing about one third of the price of its rivals such as the Commodore 64 while having a faster CPU and a better BASIC interpreter, the machine sold well in many guises throughout the 1980s and had more than a staggering 9,000 software titles. The machine may well have done well in the US too, had Timex — the company building the machine under license in the US — not already been in financial trouble and about to fold. The machine was also extremely successful in Russia, although not for Sinclair Research — because the Russians made dozens of different clones of the machine, and did so right into the mid 1990s. The machine still has a healthy retro scene, including the development of new commercial software by Cronosoft, and new hardware such as the DivIDE, which allows a standard PC hard disc or compact flash card to be connected to the machine."
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25th Anniversary of the Sinclair ZX Spectrum

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  • Z80s all around us (Score:4, Interesting)

    by Anonymous Coward on Monday April 23, 2007 @08:55AM (#18839077)
    A friend who did ASM on these chips said that the Z80 processors and variations there of is still (or at least until recently) the most common microprocessor in the world.

    Apparently they are common in dishwashers, washing machines and other programmable appliances. (Can your dishwasher run Linux?) []
  • by fruey ( 563914 ) on Monday April 23, 2007 @08:55AM (#18839079) Homepage Journal

    I started with a Sinclair ZX81, 1Kb of RAM expanded to 16Kb with a "RAM pack" that had an edge connector to the main PCB inside. It got hot (as did the power supply) and was often unstable. You could suddenly lose everything you were working on because the system just froze.

    Along came the ZX Spectrum, 48Kb (and later 128Kb) with 8 colours (the ZX81 was black & white), sprites (the ZX81 was limited to the built in character set which included blocks & things until someone worked out how to hack that) and rubber keys (the ZX81 had touch sensitive membrane things).

    It was a revolution, at my school we swapped tapes which didn't always load, had multiface cartridges to enter POKEs (changing a value at a particular memory address) for cheats and in order to create backups... and a big magazine scene.

    I even ran an emulator on my PC to play one game in particular: the game that everyone tried to beat, and still fiendishly hard (and created by a mysterious genius who "disappeared", Matthew Smith []) : Manic Miner [] (link to a Windows version).

    Those were the days []. The UK 8 bit scene was dominated by this machine.

  • Thank you Sir Clive (Score:5, Interesting)

    by LordSnooty ( 853791 ) on Monday April 23, 2007 @09:03AM (#18839143)
    Here's me and a million other Brits aged 25-35 saying 'thank you' for the Spectrum. If it wasn't for this little rubber wonder I doubt I'd be sat at this desk today, working in IT as a career. I'll be botting up the emulator" [] tonight to celebrate!

    It's also worth noting Amstrad's healthy attitude to the retro scene (they bought Sinclair Research in 1986, and many of those million Brits will think of Spectra every time they watch The Apprentice...). Anyway, the Spectrum ROM was cracked & emulated before permission was sought. When someone decided to approach Amstrad to seek permission, one Cliff Wilson [] stepped forward with a simple reply: "Yes, do what you like with the Spectrum ROM, just don't charge money for it and don't remove our copyright message." Such an open attitude towards the scene in 1999 means that it's still thriving today.
  • by Anonymous Coward on Monday April 23, 2007 @09:05AM (#18839145)
    Interestingly though (and a bit OT) a variation on the Z80 processor was used for Nintendo Gameboy.
  • by Admiral Ag ( 829695 ) on Monday April 23, 2007 @09:16AM (#18839231)
    Me too. Seeing this thread made me feel really happy and pretty old at the same time.

    A 48K Spectrum was my second computer after a ZX81. I don't think I ever got so much pleasure out of any other possession I had as a child (and I didn't even have Sam Fox Strip Poker [props to those who actually remember her, and double to those who remember the game]).

    The Spectrum just went to show how limited hardware resources would force game developers to write creative, original and addictive games. Knight Lore, RedHawk, Manic Miner, Heavy on the Magick, Spellbound, Knight Tyme, Skooldaze, Sweevo's World and above all Lords of Midnight and Doomdark's Revenge were among the best games I have played on any platform. Shame on game developers for the formulaic crap they spew these days.

    Does anyone else remember CRASH magazine? Whatever happened to those guys? It was almost worth being a spectrum owner just for that mag. Best and funniest game reviews ever, and Oliver Frey's covers were fantastic. For years I wanted to meet a girl like the one on this cover he did. es/Crash/Issue18/CRCover18.jpg []
  • by dkf ( 304284 ) <> on Monday April 23, 2007 @09:28AM (#18839339) Homepage
    I learned to write machine code on the Speccy. This was because the manual came with a listing of all the X80 instruction set, and a printout of a disassembler in a magazine showed me how to put it together. Once you've written machine code (not assembler, honest direct machine code) for a while, you learn to really appreciate what a pointer is and high-level programming languages like C hold no great terrors. (Curiously, it took me a long time before I thought of writing an assembler...)

    The Speccy was also an excellent platform for hardware hacking. That excellent manual gave you a complete description of the expansion slot, and that meant you could fabricate your own add-ons using an off-the-shelf connector, some veroboard, a simple TTL logic chip and plenty of solder. What better way to learn practical robotics?
  • I was a zx pirate (Score:2, Interesting)

    by jerryatrix ( 984426 ) on Monday April 23, 2007 @09:37AM (#18839411)
    I'll admit I ordered games from Britain, copied them and sold them to my mates and people I hardly knew. I was only 13. Attic Attack was a big seller. Happily my life of crime finished there, and my life of programming took off.
  • by Alioth ( 221270 ) <no@spam> on Monday April 23, 2007 @09:42AM (#18839447) Journal
    I've also made a 25th anniversary hardware project for the Sinclair Spectrum - an add-on board to be used for helping diagnose problems with sick Sinclair Spectrums: []

    It uses LEDs to display the test progress and status, so even if you can't get a picture out of the Spectrum, you can at least find out if the CPU and memory is working, and a good idea whether the ULA is servicable.
  • Homage post (Score:3, Interesting)

    by fsmunoz ( 267297 ) <fsmunoz&member,fsf,org> on Monday April 23, 2007 @10:08AM (#18839691) Homepage
    Not really much to add, but I feel compelled to post in homage of the computer that changed the life of so many people, including my own.

    My very first computer was a ZX Spectrum 48k. I still remember the beautiful banner: "(c) 1982 Sinclair Research, Ltd. Chuckie Egg II was my very first game, and BASIC the very first programming language I tried. The ZX Spectrum and the Timex had an almost monopoly here in Portugal in the '80's, to the extent that I never really saw a C64. The Timex plant in Portugal continued making them after the main branch closed its doors, and exported the machine to several countries (Poland was one of the main markets IIRC).

    To Sir Clive: Hip! Hip! Hurrah!
  • Nostalgia time (Score:3, Interesting)

    by scrm ( 185355 ) on Monday April 23, 2007 @10:09AM (#18839711) Homepage
    I started with a ZX81 and its 1kb of RAM, little flush keys and built-in BASIC. Moved up (or should I say 'was moved' - I was five years old) - to a ZX Spectrum when that came out. Ahh, the white-knuckle action of Arcadia []! The blistering platform mayhem of Horace and the Spiders [] (by Psion no less)! I spent many a late night (sometimes not retiring until 8pm) hammering away at the rubber keys, navigating some hideous pixellated sprite.

    Damn I can still hear the staticky 'eeeeeee-ktsch' of the tape drive now.

    Modern computing seems so flat, routine and devoid of character by comparison. What happened?
  • by Alioth ( 221270 ) <no@spam> on Monday April 23, 2007 @10:09AM (#18839719) Journal
    The 6502 had fewer registers and fewer instructions - it took more code to do the same thing. A Z80 could do a 16 bit add in 11 cycles - it took the 6502 around 20 cycles to do the same thing. The fastest 6502 instructions took 3 clock cycles to complete, the fastest Z80 instructions took four.

    Machines like the BBC Micro got better performance than the Spectrum not from the 6502, but because they had more hardware support which meant the CPU didn't have to do everything. But a BBC Model B, while undoubtedly a mighty machine and much more powerful than a Spectrum cost three times as much as a 48K Spectrum. Again, the Commodore 64, at the Spectrum's launch, was three times more expensive and had less RAM available to the user for BASIC programs.
  • Memories (Score:3, Interesting)

    by CrazyTalk ( 662055 ) on Monday April 23, 2007 @10:14AM (#18839799)
    I remember that machine well - a friend of mine actually had one. Without the memory expansion pack, it was pretty much useless. Still, if you you wanted a computer (And who didn't?) you couldn't get any cheaper than that. I remember towards the end, they were literally giving them away for free at our local service station with purchase of an oil change.
  • ZX Spectrum book. (Score:2, Interesting)

    by BiscuitTheCat ( 628652 ) on Monday April 23, 2007 @10:33AM (#18840025) Homepage
    Finally, I can post this without feeling like off-topic pimping... I've actually written and published a book ( []) on the ZX Spectrum (full-colour, coffee table format) which I decided to do last year as a 'tribute' to the machine that defined my youth... The Spectrum was a fantastic machine for the time, even though it had weedy sound. It's a shame the Clive lost his way after the Spectrum+ and didn't add enough improvements to the 128k edition of the machine. I wonder if things would have been different if he'd just repackaged the American enhanced Timex TS2068 and brought it over. Still, even though I lot of my friends had Commodore 64s ( []), I still preferred the speccy. Andrew
  • by Angostura ( 703910 ) on Monday April 23, 2007 @10:37AM (#18840063)
    At University, I connected my Speccy to the student union TV station's BBC model B (used as a caption generator) via an RS232 lead. I then wrote a rather nifty program that used the Sinclair + Microdrives as a file server for the BBC (which only had a cassette interface installed). Ah, happy days.
  • by ps236 ( 965675 ) on Monday April 23, 2007 @10:48AM (#18840199)

    The 6502 was a poor comparison to the Motorola 6809 - which was arguably the best 8 bit processor ever []. :) It drew on the strengths of the 6502, but then went better - it had many 16 bit registers (D, X, Y, U, S), full 16 bit indexing (unlike the 6502's crude 8 bit indexing), dual stacks, built-in 8 bit multiply operation, and had the 6502's '1 clock cycle per basic operation' speed - and ran up to 2MHz - which was many times faster than a Z80 with its n cycles per operation. (Hitachi's 6309 clone of the 6809 can be reliably overclocked to 5MHz!)

    The 6809 "chipset" included the 6883 SAM chip which did the 'graphics uses the RAM whilst doing the refreshing on the back-cycle' stuff years before the C64 came out...

    If the 6502 was the 'RISC' chip of the time, the 6809 was definitely a CISC chip (eg the 16 bit indexed compare 'CMP Y, S+523' would be a single opcode), but it ran at the same (or faster) clock speeds as the 6502 with few if any unnecessary cycles.

    I never really understood why Commodore chose to use the (by then 'obsolete') 6502 for their computers when the 6809 had been out for a while and was far better. The only reason I can think of is that they knew the 6502 from the Commodore Pet (which came out in 1977) and carried on using what they knew, even though it was outdated by then (the 6809 was released in 1979, 2 years before the VIC-20). (Although Commodore DID add a 6809 to their 'SuperPET' to give it some oomph)

  • by gaspyy ( 514539 ) on Monday April 23, 2007 @10:52AM (#18840249)
    Living in Eastern Europe, we didn't have access to most western hardware/software.
    When I was 7, my father built a 48K Spectrum from scratch using smuggled components (the Z80 processor, the EEPROMs), parts from other computers (the case and keyboard); he made the PCB by himself as well as copying and programming the ROMs. I still remember the hardware debugging sessions.

    Later we managed to make the Interface II (I think that was its name) addon board and get a floppy drive to work. It was an East-German Robotron 5.25" drive; we were using 360Kb Bulgarian floppies (sorry, can't remember the brand).

    It was a wonderful machine and it's the way I got into computers and learn assembler (Zeus ruled). At 12 I was busy cracking the games' copy protection to be able to copy them from tape to disks. Oh, btw, games had to be smuggled in too - one network used airline pilots, some of the few kind of people who could travel outside the country with ease. Don't get me started with books, it was hard even to photocopy one, as access to photocopiers was restricted.
  • by Alioth ( 221270 ) <no@spam> on Monday April 23, 2007 @10:57AM (#18840325) Journal
    Yes, the BBC Micro was definitely the mightiest of the 8 bits - without a doubt. The BASIC interpreter was definitely the best of the bunch (it had a built in assembler, too) and it had great support for hardware add-ons. We had Beebs at school and an Econet network (which IIRC was simply a matter of adding an extra chip to a socket in the machine). A friend and I wrote a MUD for the BBC and Econet, loosely modelled on Shades. It was an ungodly mix of BBC BASIC and 6502 assembly (and it was a surprise it ran at all), but it had client-server aspects as well as peer-to-peer aspects before either of us who wrote it had heard either of those terms. Fun times.
  • by Dogtanian ( 588974 ) on Monday April 23, 2007 @10:59AM (#18840359) Homepage

    Sr Clive also gifted us with the Sinclair QL, another product the market largely ignored despite its potentials.
    From what I've heard, the problem with the QL was that it was marketed to businesses, not the enthusiast market. I've also read that the QL was quite flakey when it launched (i.e. lots of bugs) and that the Microdrives were unproven; much as I hate to say it, I would not have entrusted my business to such a machine, even if it was technologically brilliant.

    The Acorn Archimedes was meant to be a powerful innovative PC. But the "market" was aimed to IBM PCs and to Amigas
    The Amiga was a fantastic and cutting-edge machine when it came out. Don't compare it against the PC which (even at its launch) was conservative and based on pre-existing off-the-shelf technology.
  • by SpinyNorman ( 33776 ) on Monday April 23, 2007 @11:38AM (#18840929)
    I worked for Acorn from '79 to -'82, primarily programming (in assembler) the 6502 based BBC micro (and it's little brother the Electron), and from what I can recall the 6502 was - at same clock speed - faster than the Z80. The Z80's main advantage was being available in higher clock speeds, althogh the 6502 did I think get up to 4MHz in the end

    While the Z80 had more registers, the 6502 had "page 0" addresses that allowed offset-only access to the first 256 bytes of RAM, which in a way made up for it. The 6502 instruction set was very minimal, and in fact was the inspiration for the ARM RISC processor designed by Acorn (originall ARM = Acorn RISC Machine, later re-acronymed as Advanced RISC machine).

    The trick with getting performance out of the 6502 (or any of the early 8 bitters) was to execute as few instructions as possible - things like the BBC Basic and Acorns's ISO Pascal (I was 1/2 of the team that wrote the latter) were written in extremely hand optimized assember. You would never do JSR sub; RET - always JMP sub instead. Never do LD A, 0 (two bytes), always XOR A, A (one byte, same effect) instead. Never JMP addr, when you knew the state of the CPU flags and could do JRZ addr (jump relative on zero flag vs jump absolute) instead.

    These are only a few examples, but it was surprising how much fucntionality you could fit into a tiny space by using efficient code like this. The Acorn ISO Pascal implementation fitted into 2 16KB EPROMS, yet packed in a full ISO compliant Pascal compiler (written in Pascal, and self-compiling to an internal pseudo-code - 16KB), the pseudo-code interpreter, run-time library (floating point, heap, I/O, etc), full screen editor (in 4KB of code) with regular expression search/replace, block move etc, and a command line interpreter.. The pseudo-code interpreter, etc, comprised the other 16KB and were all written in super-tight assembler... and the interpreter had to self-relocate itself out of EPROM into RAM to be able to run the compiler since the two 16K EPROMS (1 = compiler in pseudo-code, 2 = p-code interpreter, etc) occupied the same address space in the BBC micro.

    Computing was generally a hell of a lot more fun back then, partly because it was new but also partly because of the challenge of getting stuff like this to run given the limitied CPU/memory resources. I hate to think how big a modern ISO Pascal implementation with all the extras (interpreter, library, screen editor, etc) would be - maybe a factor of 1000 times bigger (32MB vs 32K) or thereabouts?!

    Those really were the good old days, although it's also exciting what's possible given the speed/memory available today.
  • by Alioth ( 221270 ) <no@spam> on Monday April 23, 2007 @11:55AM (#18841255) Journal
    Rwap services sells brand new (made in 2007) keyboard membranes for Spectrums for about 8 quid. []

    Also rubber keyboard mats if yours has worn out.
    I still frequently use my Spectrum (well, ahem, one of my FOUR Spectrums - a rubber keyed 48K, a Spectrum+, a toast rack 128, and a bare board I use for testing hardware) because they are still a lot of fun. These days, you can download most of the software from World of Spectrum. On a rainy day, it's good fun to pull out the Speccy, download a game onto my laptop, and use 'playtzx' to turn my laptop into the world's most expensive Spectrum datacorder and load a game onto the machine.
  • by Weedlekin ( 836313 ) on Monday April 23, 2007 @03:49PM (#18844405)
    "early all of the video cards were not memory mapped. I know, I used to run a store that sold these."

    While this is true, you obviously don't know _why_ they were built this way, otherwise you wouldn't be spouting tripe about it being due to a limitation in the Z80 (then again, it's hardly surprising that what amounts to a computer salesman is pretending to know far more about technical details that is in fact the case). Remember something called CP/M 2.2? CP/M itself took up 7K from the Z80's 64K maximum address space, and people who wanted to run popular software like WordStar wanted all the rest for their applications. Memory mapped graphics on CP/M business machines were not therefore a practical option, so manufacturers adopted a strategy of writing to ports instead.

    "Perhaps you were not fully familiar with all the Z-80 sellers. Northstar, Cormenco"

    It was Cromenco, not Cormenco. I was more usually involved with Micromation equipment. They made an MP/M based multiuser system that could have up to 16 independent Z80 computer cards in it, one of which would act as a master I/O controller, with the other 15 serving one user each. It absolutely blew most of the single CPU timesharing minicomputers of the day out of the water in terms of multiuser performance.

    "Essentially everything that was s-100 bus worked this way"

    Again, rubbish. The S100 could be configured as two independent 8 bit buses or a single 16 bit bus. It was quite feasible to put memory expansions for a Z80 on it, and memory expansions are by by their nature _memory mapped_. It also had advanced features such as bus-mastering that PCs didn't get for well over a decade.

    "The same was true for most early CGA using the IBM bus."

    All CGAs were memory mapped, from the very first to the very last. This page has details about them: []

    "Essentially none of the early implementaitons were able to use this"

    This is utter and complete baloney. No production Z80 was shipped without a fully working DRAM refresh system.

    "Anyhow my main point was about the megahertz myth not these details. 6502s were much less of a kludge than the z80 which was an augmented 8080 instruction set."

    Considering how (to be kind) light on facts the rest of your post is, this particular assertion obviously needs to be taken with a few Dead Sea's worth of salt..

Each honest calling, each walk of life, has its own elite, its own aristocracy based on excellence of performance. -- James Bryant Conant