Cray Operating System

The Cray Operating System ( COS) of the company Cray Research was a proprietary operating system for supercomputer Cray -1 ( 1976) and Cray X -MP and remained the main operating system of this platform until it was replaced in the late 1980s of UNICOS. COS contained the Cray Assembler Language ( CAL), Cray FORTRAN (CFT ) and PASCAL.

Since COS was written by former employees of the company Control Data Corporation (CDC ), the command language and the internal organization had a strong resemblance to the operating system Scope of the CDC 7600 and Exec 8 ( CDCs from previous ERA / UNIVAC origin). Orders were transmitted by means of the user front-end computers over a high-speed interface and so-called " station software" for COS. As a front end usually large mainframes from IBM or Control Data were used, however, DEC VAX were used. Although an interactive use of COS was possible, but most users simply started batch runs.

Disk -resident data sets that used a user program were held locally in each case. Upon completion, the local data are written back to the memory and released. To keep records on the number of processing across them, it had to be explicitly marked ' permanent' as. Magnetic tapes were also supported on Cray systems, which were equipped with an I / O subsystem.

COS enabled job scheduling and the use of breakpoints / reboot to handle large workloads can - even downtime of the system time ( planned and unplanned).

Intern COS was divided into a very small message be transmitted EXEC and a number of system task Processors (STP). Each STP was comparable with the previous peripheral processor programs CDC operating systems. However, since the Cray had no peripheral processors, led the main processor of the operating system code.

Although the program code has been released Version 1.13 of the public domain, there are no copies of it. The latest version 1.17 available as a binary file on archive.org.