There are several Apple 1 clones made! The Replica-1 by Vince Briel is the first to apply modern components to replace the hard to get and therefore expensive components, like the Signetics 2513 and such, with modern microprocessors emulating the terminal part. I found another one, with a dutch background, manufactured and sold by Achatz Electronics, the A-One. The design of this clone is similar: the terminal part is replaced by (this time two) microcontrollers, for video and serial interface.
Some differences between the two designs:
- The A-one is even more compact, less IC’s
- Has a real Apple 1 slot instead of the pinheader on the Replica-1
- No parallel keyboard interface on the A-One
- Selection of NTSC or PAL on the A-One
- The Replica-1 has USB also functioning as power supply as an option
- The Replica-1 has an AT(X) power connector, required for the -12V of the serial Apple keyboard
- The forum of Briel Computers for the Replica-1 gives good support for the community
Achatz Electronics also sells a prototype board, or a breadboard prototype board.
What really made me buy the A-One also, is the A-One Extended version. The extensions on the standard A-One are a large breadboard and three Apple 1 slots. Together with the breadboard prototype board this make it quite an impressive system to develop hardware for 6502 systems.
The design of the A-One is well documented and open: see the excellent website of WISclub member San Bergmans