liftoff : a 2018 brand new game for a very old computer

laurent974laurent974 Posts: 67
edited 2018-10-15 - 08:25:30 in General Discussion
Some guys are incredible for resurrecting old computer.


It took 4 years for 4 persons to do that.

Could that be done in P1 ? or P2?

Precisions here (in french) for the assembly code:


  • It looks like a variation on a theme of the original Jetpac game for the Sinclair ZX Spectrum.

    Our very own Baggers did a conversion over 11 years ago.

    So, it was one person who did this in about 3 months ;-)

    Shows the true power of the Prop!
  • Fantastic. Do you still have the source code? I would like to read it but the download link is down.
  • potatoheadpotatohead Posts: 9,787
    edited 2018-10-15 - 20:39:16
    Hey, that machine has a 6809! Took a quick look at the code. Compiled sprites.

    And some respectable graphics modes too. Looks like a fun old machine.

    P1 can do this game, with a very similar display. It will take some wizardry to get the display on par. Maybe a compromise or two there, using sprites and tiles, because RAM is tight.

    For reference, SPIN on P1, which get compiled to bytecode will run instructions at roughly the same rate as the 6809 will at 1mhz. Some things will be faster, others a bit slower.

    This game logic would work in SPIN.

    PASM is a lot faster, roughly 20x. It would do sound and a video engine suitable for this game.

    Great work on that one, BTW! Looks fast and fluid. Well done labor of love on the beautiful 6809. And that 6809 looks to be seated in a fine machine too. Cool stuff.

    On a P1, graphics would be a compromise. 16 colors is no problem, but there is not room for 2 higher resolution pages. Tough challenge there. Play could be on par, IMHO.

    Honestly, the P2 can probably run the game code you have in an emulation. It is an order faster and bigger than P1 is.
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  • laurent974 wrote: »
    Fantastic. Do you still have the source code? I would like to read it but the download link is down.

    I've sent a message to Baggers hopefully he'll be able to help with the source code.
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