Looking for microcontroller for computer project
An interesting option for a retro-computer is to use an FPGA; this 6809 implementation runs on a $99 Digilent Spartan-3 board. I tried it a few years ago - it worked very well with a VGA monitor and PS2 keyboard plugged into the FPGA board. Several similar systems have been designed, including this Apple II which uses an Altera FPGA board.