Hm, since some minutes, I do not need one device, but two.
First is for a Fidelity Chess Challenger Voice (1979)It demands 8.5V AC (9V still doing well) and 1100 mA (1000 still working well), and alternate current. It is likely that I solved this thing by finding an AC device that matches these values, I just need to cut the wires and attach the old 2-pin-plug to it, isolate it, and hope it works.Second is more tricky, a Fidelity Chess Challenger Sensory Champion (1982). It wants to be feeded with 8.5V (9V) AC and 1500mA. such a device I am seaaching for on the web, ebay, chess computer sites. So far in vain.Will try if the first power unit also works for the Champion, despite the lesser Amperes. I also did not manage to get positive replies from electronic stores if their are adapaters for thes terriubly old connectors. The computers have fixed wires ending in two-pin-connectors, 1mm thick, 4 mm separate, however, the CC Voice has not two poins, but one pin is replaced by one small "square". These plugs I haven'T seen since went to school, and younger salesmen in the electronics sections of warehouses even do not know what I am talking of. Collecting old chess computers is nice - as long as nothing brakes down...