Casio Micro-Mini M-800 is a historic, pocket-sized calculator from 1976 Japan.

Fully restored

Full set with original box and manual

Maybe the only one in the world

Unbelievable condition 

The Casio Micro-Mini M-800 is a historic, pocket-sized electronic calculator released in November 1976.

It is highly regarded by collectors as a major milestone in calculator miniaturisation and early Liquid Crystal Display (LCD) technology

• Size: It earned the nickname "matchbox calculator" due to its tiny dimensions of 43 x 62 x 14 mm.
• Portability Marketing: In 1970s marketing campaigns, Casio frequently advertised it alongside a standard golf ball to emphasise its palm-sized footprint.
• Finishes: The model was produced in Japan with several casing variations, including a highly recognisable mottled-gold metallic finish. 

• Display: It features an 8-digit LCD screen. Early versions used a distinct yellow-tinted light filter over the LCD to shield the fragile crystal compounds from harmful UV rays, while later revisions phased in a clear LCD screen.
• Functions: It is a basic 4-function arithmetic calculator (addition, subtraction, multiplication, and division) using standard algebraic logic across 18 physical keys. It lacks advanced percentage or memory keys (which were later introduced on the sister model, the M-810). 
• Power: It operates on a single 1.5V LR44 (or 1.2V) button cell battery. By shifting away from power-hungry vacuum fluorescent displays (VFD) to a passive LCD panel, Casio managed to squeeze an impressive 60 hours of continuous runtime out of a single tiny cell. 
• Original Retail Cost: When launched in late 1976, it carried a retail price of $29.95 USD (approximately £16 GBP at the time)

Utterly amazing