A guide to the evolution of development of architecture of the ZX Spectrum

edited June 2016 in Hardware
New! Black_Cat Info Guide #10 "A guide to the evolution of development of architecture of the ZX Spectrum" http://zx.clan.su/forum/7-160-1#1060
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Post edited by Black_Cat on

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  • This document made a distinction between the ZX Spectrum, his clones (ZX) and compatible computers (non ZX), the diagram of the evolutionary development of architecture of clones of ZX Spectrum and compatible computers.
  • How are you defining the dates for each model?
    My rubbish website including the redrawn Amstrad schematics and the new home of the Sinclair FAQ wiki.
  • guesser wrote: »
    How are you defining the dates for each model?
    Through research of existing information.
  • I meant is it by release date, earliest build date, or something else?

    You have the +3 as 1988 but it came out in 1987. I'm not when the +2A actually went on sale but it was designed at the same time. The +2B and +3B boards are (c) 1988. Again not sure when they actually went on sale.
    My rubbish website including the redrawn Amstrad schematics and the new home of the Sinclair FAQ wiki.
  • guesser, I will be grateful to you for providing links to any specific information.
  • edited June 2016
    The +2A/+3 motherboard is (c) 1987, and the +3 was released the middle of that year. I can't find the articles and ads because the magazine scans aren't available at the moment. I don't know when the first cite of the +2A going on sale was, and I've had no luck finding anything in the magazines about the +2B and +3B. It seems like no-one really noticed the change or thought it worth reporting, I don't think Amstrad made any announcement of it.
    Post edited by guesser on
    My rubbish website including the redrawn Amstrad schematics and the new home of the Sinclair FAQ wiki.
  • guesser wrote: »
    The +2A/+3 motherboard is (c) 1987, and the +3 was released the middle of that year. I can't find the articles and ads because the magazine scans aren't available at the moment. I don't know when the first cite of the +2A going on sale was, and I've had no luck finding anything in the magazines about the +2B and +3B. It seems like no-one really noticed the change or thought it worth reporting, I don't think Amstrad made any announcement of it.
    OK, ZX Spectrum +3 fixed. Thank you guesser.
  • Black_Cat wrote: »
    New release! BC IG #10 "USSR Evolution ZX Spectrum" http://zx.clan.su/forum/7-160-1
    Use only the most recent version of the "USSR Evolution ZX Spectrum"!

    Download without going to the forum.
  • The list is impressive and looks very comprehensive, but if I may, some clones are missing:
    - SpeccyBob (http://www.zebadger.com/speccybob/) - Western clones like Harlequin started there around 2001
    - Chrome (http://aticatac.altervista.org/portale/?q=node/2) dated back to 2004 and its re-creation in 2016/2017
    - Zaxon's Just Speccy 128K - 2015 (???)
    - ZX Nuvo/Omni from Superfo that are the next step from Harlequin 128 - 2017
  • edited July 2017
    I did not put before himself the task to enumerate all the existing clones. My goal was to trace the evolutionary path of development of the architecture of the ZX Spectrum. To achieve this goal, there is no need to list the hundreds of clones that have no evolutionary development. These clones are designated as "Many others." For all time of existence of the ZX Spectrum, its development occurred only in the Eastern bloc countries. In the West, the architecture of the ZX Spectrum had no development, so Western clones not represented in this guide.
    Post edited by Black_Cat on
  • Fair enough but I can't find Elwro 800 Junior and Meritum on the list.
  • Computer MERITUM as far as I can tell, has nothing to do with the ZX Spectrum and Elwro 800 Junior computer does not contain the evolutionary development of the architecture compared to the ZX Spectrum. Peripheral devices such as disk interfaces, etc. are not evolutionary development of the architecture of the computer. Evolutionary development of computer architecture involves the development of such systems as memory Manager, expanded video mode, the expansion bus, interrupt controller, DMA.
  • Is there an English version?
  • edited July 2017
    All text duplicated in English and Russian, so Cyrillic text might be ignored. Proper names are given in transliteration, i.e., how they are pronounced in Russian. For example, a clone of "Moscow" in transliteration would be "Moskva".
    Post edited by Black_Cat on
  • Thankyou. That was a lot of work and not what I expected, unfortunately! I was hoping for an explanation of the Spectrums basic architecture then followed by an explanation of the changes made to the circuitry and the advantages.

    Let me explain. I'm not an electronics engineer, just an ordinary bloke interested in the way things work. Its always intrigued me that this machine and its various spin offs have lasted for so long. I don't believe it was just thanks to being the first to fill a niche in the market, the Z80 processor seems to have had an unusually long life which would suggest that it has something special going for it (not just price). Of course the chances are that an explanation might not make much sense to me anyway but I'm prepared to give it a try!

    Thankyou for all your hard work.
  • Originally, this guide was created in order to create an evolutionary tree of architecture of the ZX Spectrum. Subsequently, the guidelines were supplemented by the evolution of the memory Manager for ZX Spectrum clones. In the future I plan to create a chronology of historic stages in the development of hardware, the ZX Spectrum.
  • I'm fascinated by things such as the pros and cons of von Neumann versus Harvard architecture ?( If I used the right term) Apparently the majority of chip designs follow the Harvard scheme whereas the Z80 used von Neumann. I dont have a clue as to what that means, I think I did look it up and did my best to cope with the explanation but it obviously didn't make an impression enough that I understand why one should be better than the other. Dont bother trying to explain it would probably be a waste of time, its little things like that which stick in my memory! I'm just interested in technical details.

    Its funny how things come and go. For example when I was a boy the best bicycle brakes were centre pull and now I see the fashion has swung back to side pull. Stuff like this intrigues me, Hence my willingness to read up on what goes on inside the computer even though 9/10 of it will probably make no sense.

    I've gone to the Zilog site and ploughed through their stuff on the Z80 and I've looked up various other details to try and get a picture of whats going on 'under the hood'. I always did want to learn more about the Eastern bloc clones because they developed the machine with such success, which I find admirable and often wondered why Sinclair didn't adopt some of these developments, instead of chasing the chimera of having the latest such as the QL which could have been a winner if they'd only used the talent available and stopped being so fixated on building down to a price at the expense of selling the machine short of what it could have been.



  • edited July 2017
    Sinclair could not take advantage of architecture of the USSR clones, because they are created after Sinclair Research Ltd ceased to exist.
    At that time there was a COCOM embargo on exports to the USSR of computer technology. The USSR's first ZX Spectrum was cloned in 1985 by Lvov engineers - enthusiasts. They are borrowed for one night a ZX Spectrum computer from foreign students, took it apart, examined the waveforms of signals ULA, copied the circuitry and on the basis of this information by reverse engineering recreated the internal architecture of the ULA. Thus was created the "Lvov prototype" . Subsequently, they handed over documentation to colleagues in Leningrad, Moscow, and Novosibirsk. Prior to 1987, ZX Spectrum clones were distributed in the USSR only among radio Amateurs. In 1987 appeared the cooperatives, who developed the PCB and have mastered small-scale production of kits for self-Assembly of clones ZX Spectrum. From 1989 to 1995, industrial companies began to produce clones of the ZX Spectrum. In 2001, the last private company has stopped commercial production of clones of ZX Spectrum. Since 2005, some enthusiasts resume development and small-scale production of clones of ZX Spectrum in exUSSR.
    Post edited by Black_Cat on
  • Cool! Thanks Black Cat - now thats what I call interesting and a tribute to the ingenuity of those responsible.
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