Well I took the electronic sign (see ad before) apart and has a z180 microcontroller board in it with a z180 cpu, 256k RAm and 256k EPROM chip (27c256), sockets for RTC and PIO chip(8155A) + few TTL type ports and RS232 interface ..no documentation ...
for people that are interested ... see pic
formatting link
best offer ...
I can post it ..