I finally hooked all parts together that I was planning for the first simple system.
It's using a W65C02, a AT28C64 eeprom, a 74HC138 for address decoding and a 6532 RIOT I got from Jameco some weeks ago.
Serial I/O is done with a MC6850 that is easy to connect to a 6502 bus and also easy to program.
The whole thing runs at 1.8432 MHz to use the main clock also for the serial clock. It's a bit to fast for the R6532, because it's the 1MHz version, but the system seems stable.
Now I need to write proper code for this thing and then it will be moved to a prototype PCB.
From now on I can truly say that I've build my own system from scratch. After nearly 30 years this idea has come to life.
Mario.