Sinclair ZX80 / ZX81 / Z88 Forums

As far as I'm aware this has not appeared on the forum, (I'm new excuse me if this is old hat) but the link below describes a ZX80 running on an ATmega88/168/328. The computer is really simple comprising of ony two IC's, it has very limited memory and no external I/O for load /save, there is however a 32 program slot external eeprom for storage. The author Miroslav Nemecek has produced a number of utilities to make the use of the computer easier and included a suite of example oprograms.

http://breatharian.eu/hw/atx80/index_en.html

I have had a play with the Jörg Wolfram's AX81 and his chip basic computer the former was a bit tricky setting up the SD card. The ATX80 circuit avoids having to use a PS2 keyboard, an off the peg zx81 keyboard could be used and relabeled I used an old one salvaged from a zx81. The whole computer could be made to fit on an Arduino shield provided the crystal was changed cheap enough to give a taste of the ZX80 and recyclable should the need arise

The ZX80 on AVR seems to be an interesting piece.
Display while executing should be possible be disabled for the correct feeling.