| Commercial Operating System (COS) | |
| Developer: | Digital Equipment Corporation |
| Released: | 1972 |
| Language: | English |
| Supported Platforms: | PDP-8, PDP-11, DECmate II |
| License: | Proprietary |
| Preceded By: | MS/8 |
Commercial Operating System (COS) is a discontinued family of operating systems from Digital Equipment Corporation.[1]
They supported the use of DIBOL, a programming language combining features of BASIC, FORTRAN and COBOL.[2] COS also supported IBM RPG (Report Program Generator).[3]
The Commercial Operating System was implemented to run on hardware from the PDP-8[4] and PDP-11 families.
COS-310 was developed for the PDP-8 to provide an operating environment for DIBOL. A COS-310 system was purchased as a package which included a desk, VT52 VDT (Video Display Tube), and a pair of eight inch floppy drives. It could optionally be purchased with one or more 2.5 MB removable media hard drives. COS-310 was one of the operating systems available on the DECmate II.
COS-350 was developed to support the PDP-11 port of DIBOL, and was the focus for some vendors of turnkey software packages.[5]
Pre-COS-350, a PDP 11/05 single-user batch-oriented implementation was released; the multi-user PDP 11/10-based COS came about 4 years later.[3] The much more powerful PDP-11/34 "added significant configuration flexibility and expansion capability."