DATAMATH PICTURES

This Royal Model 91K (UA121) was manufactured in September 1975 in Japan.

The Royal Model 91K (UA122) is powered by four disposable 1.5 Volt batteries.

The Royal Model 91K (UA122) calculator with the frontside of its housing removed.

The printed circuit board (PCB) of the Royal Model 91K (UA122) is centered
around a NEC µPD947 single-chip calculator circuit.

Close-up view of the NEC µPD947 single-chip calculator circuit.

Close-up view of the FUTABA 9-ST-12 Vacuum Fluorescent Display (VFD).

Front- and backside of the keyboard assembly of the Royal Model 91K (UA122) calculator.

Close-up view of the date code located on the GICO keyboard assembly.