Cray Operating System
| Cray Operating System | |
|---|---|
| developer | Cray Research |
| License (s) | Proprietary |
| First publ. | 1975 |
| Current version | 1.17.2 (July 1990) |
The Cray Operating System ( COS ) is a proprietary operating system from Cray Research for the supercomputers Cray-1 (1976) and Cray X-MP . It remained the platform's main operating system until it was superseded by UNICOS in the late 1980s . COS included the Cray Assembler Language (CAL), Cray FORTRAN (CFT) and Pascal .
Since COS was written by former employees of the Control Data Corporation (CDC), the command language and internal organization were very similar to the Scope operating systems of the CDC 7600 and Exec 8 (from CDC's earlier ERA / UNIVAC origins). User orders were transferred to the COS using front-end computers via a high-speed interface and so-called "station software". Large mainframes from IBM or Control Data were usually used as the front end , but DEC VAX were also used. An interactive use of COS was possible, but most users simply started batch -Läufe.
Disk resident data sets used by a user program were held locally. After completion, the local data was then written back and the storage space was released. In order to keep records over several processing operations, they had to be explicitly marked as 'permanent'. Also, magnetic tapes were supported on Cray systems, with an I / O were equipped subsystem.
COS enabled job scheduling and the use of breakpoints / restarts to handle large workloads - even across system downtime (planned and unplanned).
Internally, COS was divided into a very small message-sending EXEC and a number of System Task Processors (STP). Each STP was comparable to the peripheral processor programs of earlier CDC operating systems. However, because the Cray computers had no peripheral processors, the main processor executed the operating system code.
Although the version 1.13 code was published in the public domain , there are no copies of it. The last version 1.17 is available as a binary file on archive.org.