I have an osc 20 in working order and it seems quite easy to operate I have managed to set the time and clear a holiday setting I dont have a User manual I have looked in side and it is based on the Z80 CPU with the software in an Eprom 27C64 8kb rom
the fast run button sequenses through the settings controling the system as well pressing AUTO will return to normal at any time I havent ventured ferther yet.
Kenn, January 2015
