Psion MC series
The Psion MC (Mobile Computer) series is a line of laptop computers made by Psion PLC. They were made from 1989 to 1991, measure , and weigh .

History 
The A4-sized, elegant notebook had an excellent 640 × 400 pixel liquid crystal display (LCD) and, at a time when Microsoft Windows was still at version 2.11 (without window management, multitasking), a graphical user interface with multitasking. Instead of a mouse, this model has a touchpad. This was uncommon in 1989: the Gavilan SC was the only widely known model with a touchpad, and they were not used again until years later. 

The newly developed EPOC16 (SIBO) operating system allowed hot swapping of the flash memory cards in the 4 memory slots, and with the two hardware expansion slots, the device seemed ready for all future developments. But it turned out differently. For one, the prices were quite high, with the MC200 at , MC400 at , and MC600 at , and the memory cards were very costly. Also, the software was not yet fully developed for market launch: the word processing was disappointing, the Open Programming Language (OPL) was adopted almost unchanged from the Organizer II and did not support the graphics abilities of the device, and professional developers had to wait over a year for the software development kit (SDK). The announced voice compression module was never finished, and apart from a parallel port, there were no hardware enhancements. Further, the press accused the device of incompatibility with the then standard IBM PC compatibles.

Sales were weak, and SIBO Version 2, released in 1990 as a free update, changed nothing, although it came up with a Microsoft Word-like word processor and a significantly improved OPL version. The slimmed-down MC200 version with a blue and white, half as high screen and 128 kB RAM (instead of 256 kB) sold even worse. The MC600 was just as hastily released into the market. This used MS-DOS as the operating system, likely in reaction to press criticism, and had 768 kB of random-access memory (RAM) and a 1 MB RAM drive, which raised the price again. The touchpad was dropped in favor of a function key bar, and the screen resolution was only 640 × 200 pixels according to the Color Graphics Adapter (CGA) standard. The machine was a flop from the start.

Models

Psion MC200 
The version of MC400 model with lower cost display and less RAM (a 256K memory and a 640 x 200 green-blue screen).

Psion MC400 
The Psion MC400 is a laptop released in 1989.

The main power is provided by eight AA batteries, or by an external 12V AC adapter power source.

The MC400 was of the same generation as the Psion Series 3, but it has a larger size screen (640 x 400 pixels). The MC400 could be programmed using OPL much like the Series 3.

Unlike the Series 3, the MC400 has 4 bays for removable solid-state disk drives compared to 2 on Series 3 devices. The serial port also provides PC connectivity if used with the separately available PsiWin software using the lead designed for the Series 3 or 3A.

Psion MC400 Word

Psion MC600 
DOS-equipped version of MC400.

References 

Psion devices
Computer-related introductions in 1989
Laptops