Memotech was one of the computer peripheral manufacturers which was kept alive by the success of the Sinclair ZX Spectrum home computers in the early 1980's. In the beginning, Memotech produced keyboards, modules, game ports and other devices for use with the popular Spectrum computer.
In 1983 Memotech introduced the first computer of it's own design, the Memotech MTX-500. The first model was soon followed by two others, the MTX-512 and the RS-128, difference between the models being mainly in the amount of the accessible memory. The cheapest model MTX-500 (£275 in 1983) had only 32 kilobytes of RAM but the best equipped RS-128 was loaded with 128 kB of it. All versions were upgradable up to 512 kilobytes of memory which was a great deal by the standards of that time.
The CPU used by Memotech was a Z80A running at 4 MHz. The text mode screen was able to show 40 by 24 characters and the graphics mode 256x192 pixels with 16 colors and 32 sprites. The computer was extensible and had versatile connections: video output for both tv and monitor, a separate audio output, a Centronics printer port and two joystick ports. The basic setup included a cassette interface operating at 2400 baud but with a separate extension box "FDX" you could also use floppy drives and a hard drive and make the computer CP/M compatible. The 79-key keyboard was, unlike many competiting products, of great quality and suitable for professional work.
Memotech was targeted towards utility use. The computer had MTX Basic on ROM and useful software like Pascal and a word processor were available as a ROM modules. The optional FDX extension box made the use of the wide range of CP/M software possible. Several games were also published for the computer, mostly by the Memotech in-house software company Continental Software. Sadly the large game companies like Ocean were not convinced about the machine's possibilities. Memotech gave up the manufacturing of MTX and RS computers after only a couple of years as the more popular home computers like the Commodore 64 ruled the market. But you can still get an almost authentic Memotech experience by using an emulator like Mt. Xemu (MTX emulator for Windows), MTXEmu (for Macintosh) or MTX (for Acorn Archimedes) .
Sources of information: the AARGH (http://www.arrgh.demon.co.uk/)
The Home Computer Hall of Fame (http://www.gondolin.org.uk/hchof/)
Albert' Virtual Computer Museum (http://utopia.knoware.nl/users/stuurmn/)
Thanks to Bemmu for the update about Memotech emulators!