AKA (Label): Model 91 S, Product number (P/N): 91S (91 S),
Keywords/Tags: 91S (91 S)
Date of intro: ~1976, Origin: Japan (List), Dimensions: 120x75x20mm, Weight: 115g,
Power: 6V: (AAA x4) + Adaptor,
Display: Type = Display (VFD) (List), Digits = 8+1,
Number of keys: 27, #Key-Black: 13, #Key-Blue: 3, #Key-White: 11,
Keyboard Array (Rows x Columns): 06x05, Keyboard Layout: [CI] [C] - [(SquareRoot)] [(Pi)] [(-)] [%] [x<>y] - [7] [8] [9] [(Division)] [CM] - [4] [5] [6] [x] [M-] - [0] [.] [=] [+] [M+],
Decimal switch: [F-2-3-off],
Classification: / Pocket,
Featuring: Procent, Square root, PI, Logic-technology: VLSI (Very Large Scale Integration), calculator-on-a-Chip,
Related with: (Docu_Catalogs): ARGOS: 1977; IMPERIAL_parts: (Box) 91S,
Components: 28 ... 8 Capacitor(s), 8 Diode(s), 6 Resistor(s), 2 Transistor(s), 1 IC(s),
Main Components: HITACHI: HD36265,
Resemblance with: TRIUMPH-ADLER: 81S (version-5); ROYAL: 91S (version-1); ROYAL: 91S (version-2), (Resemblance 033),
Known Serial-numbers: 91S69252697 (91S 69.252.697) | 91S69276314 (91S 69.276.314) (List of all S/Ns from IMPERIAL)
Collector value: 7/10,
Internet: Link-1: VINTAGE TECHNOLOGY, Link-2: VINTAGE CALCULATORS WEB MUSEUM