Revisiting A Z80 Game From 1990

Back in the days of 8-bit computers, like no doubt many readers of similar age, we wrote little games. First in BASIC, then augmented with little machine code speed-ups. We didn’t come close to [Óscar Toledo Gutiérrez] though, who’s reverse engineering a 2K all-machine-code game he wrote back in 1990. As a tale of software archaeology it’s fascinating.

The game itself is an avoid-the-monsters platformer with plenty of ladders for the little sprite-based protagonist to run down. The computer was a Mexican homebrew educational machine with a TMS9118 display chip and an AY-3-8910 synthesizer, so the result had both color and music. His run through the code breaks it down neatly into individual sections, so it’s possible to see what’s going on without an in-depth knowledge of machine code.

He readily admits it bears all the hallmarks of an 11-year-old’s knowledge at the time, and that it has some parts less elegant, but nevertheless it’s something of an achievement at any age. It was out of date gameplay-wise in 1990 but in 1982 it could probably have been bought on a tape by eager kids. Here in 2024 he’s got it for download should you have a Colecovision or an MSX. There’s a gameplay video below the break, take a look.

16 thoughts on “Revisiting A Z80 Game From 1990

  1. “The computer was a Mexican homebrew educational machine with a TMS9118 display chip and an AY-3-8910 synthesizer [..] ”

    MSX1, TI99 and that NABU thing used that same humble VDP, too.

    It’s no wonder that MSX1 didn’t catch on.
    The MSX2 with succesor V9938 turned out to be very successful in the end,
    but the “harm” caused by MSX1 was already done.

    Here in Europe, only a few MSX2 computers were being sold.
    No one apparently had believed it would be successful.

    1. The Spectrum was much worse and it was popular. MSX1 was very popular in the Netherlands and the MSX1 Spectravideo 728, even the pre-MSX1, the Spectravideo 328, was pretty popular in Scandinavia. In Japan and Brazil the MSX was really huge.

      1. I think they were popular because of the Z80 and open design.

        Both ZX Spectrum and MSX could be cloned using standard parts.

        Not much unlike Taiwanese no-name XT motherboards used by Turbo XTs.

        ZX Spectrum was heavily being cloned in east Europe back in the days.
        MSX officially was an open standard, also.

    2. You don’t speak for the entirety of Europa, sugar.

      In the Netherlands, Spain and other countries they sold tons. Especially when you start counting unofficial clones of the MSX 1 and 2. Especially in East block countries those were quite common.

      Just because the specs might not be “as good” doesn’t mean it’s a worse computer. If that was the case Apple would have been blown away by Commodore. Price also matters. And the MSX was just cheaper than a C64, with more software and a better version of Basic so that anybody could program simple procedures.

      1. “You don’t speak for the entirety of Europa, sugar.”

        Aye. Sorry, I never meant to do so.

        In an earlier post some weeks (?) ago I mentioned a source about MSX popularity.

        I think it’s this one:
        https://www.pcgamer.com/the-bright-life-of-the-msx-japans-underdog-pc/

        MSX1 also existed in various home computers that weren’t being advertised as MSX machines.

        MSX2 had still been sold in Europe, yes, but by that time, MSX as a brand was being largely obsolete.

        – The popularity/market share of MSX2 was below of that of MSX1 in its heyday, I mean.

        MSX2+ and Turbo R were pretty much Japan-only.

        There’s a fine MSX community that still develops for MSX, also.
        Some members also try to convert MSX machines to the much better MSX2.

        The problem is, that some MSX1 machines do have some MSX2 features, but do lack MSX2 Basic or don’t have the correct mapping.

        They’re MSX 1.5, so to say.
        They have more memory or the 9938 VDP, but can’t run MSX2 software.

        If memory serves, there’s even an upgrade cartridge with a new MSX system software. 🙂

      2. “Just because the specs might not be “as good” doesn’t mean it’s a worse computer. If that was the case Apple would have been blown away by Commodore. Price also matters. And the MSX was just cheaper than a C64, with more software and a better version of Basic so that anybody could program simple procedures. ”

        Oh, come on! 😃 Even back then people had standards.

        The 99118 and 9938 & up do compare to each others like CGA vs EGA.
        Or Atari 2600 vs Intellivision. Or VC20 vs C64.

        The MSX1 computers aren’t bad by any means, it’s just that their graphics is on ZX Spectrum level.

        Anyway, I’m no graphics guru whatsoever.

        I’mjjust thinking that these machines necessarily had limited the artistic talent of their users.

        If you have a 3×3 field (tic-tac-toe playfield), you have finite possibilities.
        It’s a mathematical fact.

        No matter your creativity/imagination, your choices of drawing are being limited, not to say all combinations are already being given.

        And same goes for that TI99 VDP.
        It doesn’t allow much combinations, doesn’t allow much freedom for expression.

        Other slightly more recent platforms do not necessarily have same narrow boundaries.
        That’s what I meant to say.

    1. And an 8080 emulator, too! Cool! Thanks for the tip! 😃
      I don’t know why the author wa.. spents his time with such low-end stuff (99118, lowrez graphics),
      but looking at the website he seems to me he’s a fine dude and quite capable at programming&graphics!
      And chess, of course! Kudos! 👍
      If he secretly was into electronics, astronomy or ham radio, too, I’d be falling off my chair right now.

      1. Up to date computers cost a lot more in 1990 than today. Also pre-internet most people saw a lot less value in owning one. Most kids had access to no computer at all in the home. I’m guessing he worked with what he had and was happy to do so.

        Revisiting it afterward… well if you put that much effort into something in the past you will probably want to revisit it one day too!

        During the Pandemic I revisited my own QuickBasic from the mid 90s and got it running and even compiling in Linux on a current computer.

        1. “Up to date computers cost a lot more in 1990 than today.”

          Yes, things were expensive.
          Though Amiga users still tell everyone their computer wasn’t. 🤔

          “Also pre-internet most people saw a lot less value in owning one. Most kids had access to no computer at all in the home. I’m guessing he worked with what he had and was happy to do so.”

          Makes kind of sense, yes.

          Or they also had a console instead, also?
          Famicom and clones used to be omnipresent in the east, while Brazil had Sega Mastersystem/Genesis.
          Arabic places, too, I suppose.

          Let’s remember there also were pre-internet online services.
          Like CompuServe, Quantum Link (aka Q-Link), AOL, Genie or Minitel.

          And certainly many others that were never known internationally.
          So there was certainly some appealing in going online early on.

          Home computers..The home computer scene here in Europe somehow had lasted longer than natural, I think.
          Probably because of techno phobia or something.

          Computers had that stigma of espionage/thought-control (big brother, 1984 novel etc) and taking away workplaces.
          That’s how it was in 1980s Germany, to my knowledge. Lots of geeks, but also lots of “worried” citizens.

          By contrast, the US had home computers early on, but the video game crash made those 8-Bit machines look less sexy.
          So they never got the later, more sophisticated home computer models anymore.

          They used PCs and Macs widely, rather.
          – Those lucky bastards*! 😁

          (*just a saying, I don’t mean it)

          “During the Pandemic I revisited my own QuickBasic from the mid 90s and got it running and even compiling in Linux on a current computer.”

          That’s nothing to be ashamed of whatsoever.
          Quick Basic supports VGA in 640×480 and beyond via SVGA library.

          You can do a lot of sophisticated stuff with it. 😃
          There are libraries for Sound Blaster, video playback, etc.

          Similarly, Power Basic also has a lot to offer.

        2. “Revisiting it afterward… well if you put that much effort into something in the past you will probably want to revisit it one day too!”

          Absolutely.

          The 8080 or 6502 code isn’t the problem, at all.
          It’s not the game concept, either.

          It’s just hard to understand that people still continue put so much energy in old graphics chips that limit expression so hard.

          With a slightly less ancient VDP, there would be much more room for expression.

          It would still be fine pixel art, but the pixel density would be good enough to draw a recognizable face or a piece of cloth.

          Let’s just think of the Famicom or Sega Genesis. Or those Japanese PCs (MSX2, PC-88/98).

          Limitations (resolution, color, memory) as such can surely be good for creativity, but taking it to an extreme (Atari 2600 level) does limit the artist again. He/she can’t use all of their talent and express themselves.

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