If that wasn’t enough, he also uses a PS/2 keyboard for input ... which can be executed by the Arduino’s ATmega328. To keep everything in ROM and make the emulator portable, [Damian] used ...

For the x86 CPU emulator, he ported Fake86 which is written in C, and created an Arduino IDE environment ... There’s no keyboard yet but he has 640×200 CGA working with 80×25 characters ...