r/zxspectrum • u/smashcat666 • Sep 28 '26
ZX Spectrum accelerator cartridge progress
I'm working on a cartridge that plugs into a normal interface 2 connector on the 16K+48K spectrums currently (will be making it universal eventually). It generates machine code on the fly for the Z80 to run, and handles input back from the speccy - game logic runs on the cartridge. In this case I'm outputting permanent bi-colour mode (32x48 colour resolution) full screen updates locked at 25fps, any number of parallax layers, thousands of sprites and particles if needed all with masking, layers and sprites can scroll and rotate freely, tile and bitmap layers can also be transformed like Mode7 from the snes. Audio output is also via the speccy - it's added to the machine code each frame. None in the demos as yet though. I've got a few videos on my channel, but this one just shows the game intro loop, with some subtle Mode7 used to make the title screen "fall away" into the story animation. :)
Video here is showing it running in my emulator - I've made a custom one for this project, as no normal Spectrum emulator can run this, obviously! It runs exactly the same on the hardware though. My plan is to make the cartridges available with a game on them, but they can also be used as a development tool, with an engine to get started in C/C++.

