ICL (International Computers Limited) is a UK based computer company and services company. ICL made numerious computers over the years including their Distributed Resource System DRS for short. ICL later just used the abbreviation in order to create ICL DRS.
There were many lines of computer under the DRS branding and later on the systems would be running their own version of ICL MS DOS 4.0 before MS DOS 4.1 was later released. These systems were on the forefront of technology and was competing against IBM in the UK market.
Later on ICL produced the PWS (Personal Work Station) line of computers which were IBM PC Clones. This series contained the M models of computer ranging from the M10 to the M80.