AKA: Scientific 21, Product number (P/N): 21,
Keywords/Tags: 21 | Scientific
Date of intro: ~1975, Origin: Thailand (List),
Number of keys: 20, #Key-Blue: 7, #Key-Red: 2, #Key-White: 11,
Keyboard Array (Rows x Columns): 04x05,
Classification: / Pocket,
Featuring: Scientific functions, Square root, PI, Logic-technology: VLSI (Very Large Scale Integration), calculator-on-a-Chip,
Collector value: 7.5/10,
Internet: Link-1: SMITHSONIAN MUSIC