The Demon Development Cartridge was an addon from John Morrison.
Now, thanks to Jose Leandro, the hardware specialist of the spectrum, with his famous page :
http://trastero.speccy.org/cosas/JL/JL.htm
We can know more about this hardware.
Pictures
Publicity
Download
- Demon (ROM).zip (ROM for Emulators)
- Demon (Eagle).zip (Demon Development Cartridge files for Eagle)