Show HN: A Sinclair ZX81 retro web assembler+simulator

Lots of fun to do. I would have not taken the time without the speedup provided by Claude.

https://andyrosa.github.io/Sinclaude/simulator.html

75 points | by andromaton 1 day ago

7 comments

  • jlundberg 10 hours ago
    For people interested in the ZX community, be sure to check out the ZX Spectrum Next (ks3 ending within a week):

    https://www.kickstarter.com/projects/spectrumnext/zx-spectru...

  • pjmlp 18 hours ago
    Looks nice, however on laptop screens not all buttons are visible, it took a while to discover I could scroll to find "Assemble and Run".
  • GPerson 11 hours ago
    Fast / slow mode breaks “Space Invader” by the way.
  • SanjayMehta 1 day ago
    I still have my zx-81, it powers up but the keyboard membrane is long gone. Learnt z80 assembly on it. Good times.
    • stephbu 1 day ago
      Yeah me too in 1982, using the Melbourne House Z80 reference, aged a young 10 years old. Working with POKE and no macro-assembler, I wrote mnemonics then translated them to machine-code by hand. A baptism of fire that to this day that I've not forgotten.

      This book was the ignition that changed my life... https://archive.org/details/z-80-reference-guide-alan-tullya...

      • rwmj 17 hours ago
        Cover art to die for too!
    • boomlinde 20 hours ago
      ZX Renew sells replacement membranes for £12 if you want to get it in working order.
    • YZF 23 hours ago
      I have my ZX-81 (with the 16KB expansion pack) and my ZX-Spectrum (with a microdrive). I think they're in working condition though they haven't been powered up like in 30+ years.
      • rwmj 17 hours ago
        Don't just plug it in! The power supply and/or VRM can fail in ways that deliver bad voltages to components. You might want to watch some of Lee's[1] videos first on how to bring up a ZX81 safely, or ask in his discord community for more help.

        [1] https://www.youtube.com/@MoreFunMakingIt/videos

        • pjmlp 12 hours ago
          That is why my Timex 2068 has never left the box since around 1990.

          Better admire for what it was and use an emulator instead.

      • JdeBP 20 hours ago
        Watching the retrocomputing enthusiasts, apart from obvious things like water damage, it seems that the first thing that one always has to check before attempting to power up is capacitors. A generalism true for all old electronics, rather than Sinclair-specific.
        • actionfromafar 19 hours ago
          And always assume the C64 power supply will fry the computer. It fails over time by raising the output voltage.
  • GPerson 16 hours ago
    Can you say what parts Claude was used for to speed this up?
    • xnorswap 14 hours ago
      My guess is most of it? This commit message for example sounds very much like a Claude result:

          Add Space Invaders game implementation in assembly language
          - Implemented the core game logic including player movement, missile firing, and invader behavior.
          - Added collision detection for missiles and bombs.
          - Included game state management for win/lose conditions and restarting the game.
          - Created functions for drawing game elements on the screen and handling keyboard input.
          - Defined constants and variables for game configuration and state tracking.
      
      
      That last one in particular is exactly the kind of update you get from claude, it doesn't sound very human. "Constants and variables" eh? Not just constants or variables, but constants and variables.

      Helpful, but not. Detailed, but not.

  • empressplay 23 hours ago
    Cool stuff! My first computer was the Timex Sinclair 1000 (when I was 6). Good times!

    We did something similar for the Apple II, to compile Merlin assembly into a running emulator instance:

    https://paleotronic.com/merlinplus/

  • sebastien_b 1 day ago
    [dead]