The Psion Organiser was the brand name of a range of pocket computer developed by the British company Psion in the 1980s. The Organiser I (launched in 1984) and Organiser II (launched in 1986) had a characteristic hard plastic sliding cover protecting a 6x6 keyboard with letters arranged alphabetically.

The Psion Organiser I model, launched in 1984 was the "World's First Practical Pocket Computer". Based on an 8-bit Hitachi 6301-family processor, running at 0.9MHz, with 4kB of ROM and 2kB of static RAM, and had a single-row monochrome LCD screen. The size in mm with the case closed is 142 x 78 x 29.3, and the weight is 225 grams.

The machine provided a simple flat-file database, calculator and clock, and had no operating system. The Organiser I supported removable storage write-once devices which used EPROM storage. The machine could host two of these so-called DATAPAKs (or simply PAKs), to which it could write data but which needed to be removed from the machine and erased by being exposed to ultraviolet light before they could be re-used. As Psion had patented the use of EPROMS as storage device it was impossible for other device manufacturers to copy this innovative approach to mobile storage.

Software supplied on DATAPAK included a crude programming language called POPL, in which end-users could write their own programs. Software DATAPAKs titled Science, Maths and Finance contained the POPL programming language editor, interpreter and runtime and extended the built-in calculator by adding named functions. These DATAPAKs also contained different sets of application programs written in the POPL language.

Our Psion 1 is in working order and it is complete with the hard case and the Utility and 8K datapacks. We are very grateful to Glenn Oliver who kindly donated our Psion.

Magazine Articles About Organiser

• Personal Computer World - August 1987
• Practical Computing - December 1987
• Personal Computer World - February 1988
• The Micro User - June 1988 - Vol 6 No 4
• Acorn User - August 2001
• Acorn User - March 1991