is an algebraically specified abstract machine
. It was developed by Foster, Currie et al. at the Royal Signals and Radar Establishment
at Malvern, Worcestershire
, during the 1980s
. It arose from earlier work on the Flex machine
, which was a capability computer
implemented via microcode
. Ten15 was intended to offer an intermediate language common to all implementations of the Flex architecture for portability purposes. It had the side-effect of making the benefits of that work available on modern processors lacking a microcode facility.
Ten15 served as an intermediate language for compilers, but with several unique features, some of which have still to see the light of day in everyday systems. Firstly, it was strongly typed, yet wide enough in application to support most languages -- C being an exception, chiefly because C deliberately (and some say obtusely) treats an array similar to a pointer to the first element of that array. This ultimately led to Ten15's development into ANDF and TDF. Secondly, it offered a persistent, write-only filestore mechanism, allowing arbitrary data structures to be written and retrieved without conversion into an external representation.
Why 'Ten15'? Legend has it that, after several failed attempts, a meeting was called to thrash out a name for the language. In desperation, it was suggested that 'we set a target - to come up with a name by 10:15'. And so they did. Other versions have it that in the course of the stalled meeting, Ian Currie
looked up at the clock and said 'Why not call it 10:15?'