Anita 851

(Crappy cellphone pics)

I'm guessing this would have been real handy at the time, because South Africa shifted from (UK) imperial measurements to metric starting in 1971 and officially ending in 1977 (but in reality we still deal with remnants, I have a set of Land-Rover tools in inches and Whitworth(!), and shooters measure muzzle velocity in feet and group size in inches and probably will for a while still).

Serial 2A 11593.

It's a three PCB sandwich of the power supply, CPU and keyboard.

I don't think there's any link between the Rockwell A4004PC (date code towards the end of 1974) and the Intel 4004. Nine transistors driving nine seven segment displays but I think the left-hand one is used to display "-" only... not sure.

My display comes on, but nothing on the keyboard works.

There's a web side dedicated to Anita calculators.