|
PRIMOS was an operating system developed for Prime computers. PRIMOS was developed during the 1970s by Prime Computer Inc. It rapidly gained popularity and by the mid-1980s was a serious contender as a mainline minicomputer operating system. With the advent of PCs and the decline of the minicomputer industry Prime was forced out of the market in the early 1990s. Prime Computer is also sometimes referred to as "Pr1me" and PRIMOS as "Pr1mos". Very early versions of PRIMOS (revision 6) were originally called DOS and later DOSVM but PRIMOS is the name that stuck. There were many major releases of PRIMOS. The last official revision (24.0.0.R52) was released July 3, 1997. By this time, a company called Peritus (which employed a number of ex-Prime engineers) was maintaining Primos. An interesting feature of PRIMOS was that it, like Unix, was largely written in a high level language (with callable assembler library functions available). At first this language was Fortran IV, which was an odd choice from a pure computer science standpoint: no pointers, no if-then-else, no native string type, etc. Fortran was, however, the language most known to engineers, and engineers were a big market for Prime in their early years. Later, around version 18, a version of PL/1: PL/P, became the high level language of choice within PRIMOS. The source code to PRIMOS was available to customers and, thanks to FORTRAN and PL/P, customers could reasonably modify PRIMOS as needed. From Revision 19, major portions of PRIMOS were written in the languages SPL and Modula-2, the usage of the assembler PMA (Prime Macro Assembler), Fortran IV and PL/P declined considerably around this time. Programs were guaranteed to run on all current Prime processors (subject to sufficient resources being available), as well as all subsequent Prime processors. The PRIMOS character set was basically ASCII but with the 8th bit set high, instead of low. This is vital to realize when transferring data from PRIMOS to almost any other system. PRIMOS systems are becoming rare but as of 2006 there are still some in production, including a number of Primes running a modified version of PRIMOS in the UK, supporting a large corporate telecommunications network.
| ||||||||
|
| |||||||||
 |
|
| |