minitron 811B

Display is 8 digits, green VFD.

4-function, %, memory.

4.5v (3x AA batteries).

Integrated circuit: [Rockwell] A5501PC (here date coded 1977, week 32)

69 mm x 118 mm x 24 mm (2.8" x 4.7" x 1").

Elektronska industrija-Niš, made in Yugoslavia (now Serbia).

To replace the batteries the rear cover slides up, which also reveals the label which shows:

Ei (Electronics industry) Factory Calculating Machines Niš.

 

Has the three-pin adaptor socket so it can be powered from the ANITA AC Adaptor while containing disposable, non-rechargeable, batteries.

The circuit board showing the A5501PC integrated circuit (here date coded 1977, week 32). This does not have a manufacturer's mark but is clearly of Rockwell heritage and has a Rockwell part number.

The black rectangular block above the integrated circuit is unusual and contains encapsulated discrete components.