 From 1986 to 1989, about 200,000 systems were sold, each costing £499, mainly to UK schools and universities.A number of enhanced versions were launched—for example, the Master 512, which had 512 KB of RAM and an internal 80186 processor for MS-DOS compatibility, and the Master Turbo, which had a 65C102 second processor.The first commercial use of the ARM architecture was in the "ARM Development System", a Tube-linked second processor for the BBC Master which allowed one to write programs for the new system.