Suspect is an incomplete 48k ZX Spectrum emulator.
The initial target is to get 48k functionality complete and correct, before moving on to support anything else.
Currently CPU is missing a whole lot still but can play a few games and boot the ROM to reach the prompt
Keyboard emulator is half working and broken (probably easy to fix with quick debugging)
Screen decoding and display is basically working
Sound is mostly working, but there is a timing bug and it gets further "behind" (and probably increases RAM usage as it goes)
Interrupts are not done properly and should be considered broken.