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Jetpac on ZX Spectrum

  • @Yorick How did you set up your controller as Kempston?

    The default joystick emulated in lr-fuse is Cursor. You can play Manic Miner with the arrow keys which explains why your controller works here.

    To change the default to Kempston, you can either change the joystick emulated in RGUI or, for a permanent solution, you can edit /opt/tetropie/configs/all/zxspectrum/retroarch.cfg as described in my previous post.

  • @dudleydes I changed the line in /opt/retropie/configs/all/zxspectrum/retroarch.cfg to input_libretro_device_p1 = "513" like you suggested.

    Then in the Jetpac game there is an option menu called peripherals with an option to select Kempston where you have to press space bar to select it and then enter to save settings.

  • @Yorick I'm not sure about the peripherals menu you are speaking about.

    This is the menu I see,87771/

    If I press SELECT on my controller, then a keyboard overlay appears. I can then use my controller to "press" 4 to select Kempston and 5 to start a game.

  • My Xbox controller doesn't work at that screen so I press 4 on my Keyboard to select Kempston and then 5 to start game. Then the game runs but my controller still doesn't work except for the B button which opens a menu where you can select option-peripherals and activate Kempston by pressing space and enter.

  • @Yorick I cannot see the "option-peripherals" - can you confirm which emulator you are using?

  • lr-fuse and run Rom as 48k

  • @Yorick I'm stumped! All I can suggest is to test with other games.

  • Sorry to dredge up an old topic, but hopefully this is a quick fix.

    I've updated my /opt/retropie/configs/zxspectrum/retroarch.cfg to add

    input_libretro_device_p1 = "513"

    And JETPAC now works fine with Kempston joystick. BUT my other favourite game is Chuckie Egg, which doesn't support Kempston.

    So for that game I need to switch the mapping to Kempston off, and go back to the default cursor joystick (which works fine).

    On the runcommand window there is an option to 'edit custom Retroarch.cfg config for this RoM' but when I type the original contents of retroarch.cfg in there, the joystick still appears to be mapped as a Kempston.

    Is there another code I need to explicitly set to revert back to a cursor joystick just for this one particular game?


  • @gtbfilms I'm pretty sure that in the RGUI you can just save a game specific configuration file that'll do the trick. I think that's how I have mine set up.

  • @dudleydes said in Jetpac on ZX Spectrum:

    @Yorick According to World of Spectrum, Jetpac runs on a 16k machine. By default, lr-fuse, which I assume is you are using, runs the the 128k machine - you will see the line fuse_machine = "Spectrum 128K" in the file /opt/retropie/configs/all/retroarch-core-options.cfg.

    If you change to 48k machine type in the RGUI, then Jetpac will run. Now this will be a pain to change between 48k and 128k machine for newer games that require the extra memory.

    This is my solution. It may be not be optimum but it works.

    In the folder /opt/retropie/configs/all/, create a text file called retroarch-core-options-fuse48k.cfg and add the following line:

     fuse_machine = "Spectrum 48K"

    Now we need to make sure Jetpac uses the 48k machine so in the ZX Spectrum roms folder, create a text file called Jetpac.tzx.cfg. The file name must match the tape so you may have to amend. In this file, add the following line:

    core_options_path = /opt/retropie/configs/all/retroarch-core-options-fuse48K.cfg

    Save and Jetpac should now run. If you take a look at retroarch-core-options-fuse48k.cfg after launching Jetpac, you'll notice RetroArch will have added extra lines. It's best to leave these.

    For any other games that run a 16k machine such as Deathchase, all you need to do is copy the cfg file and rename it so that it matches the tape.

    Hello Dudleydes,

    Apologies for digging this post from it's grave, but I'm struggling trying to get your fix to work for loading 48K Roms in LR-Fuse? Is there any chance you could give me some guidance?

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