Commercial Operating System (COS)


COS-3xx was the name used by Digital Equipment Corporation for a family of operating systems.
They supported the use of DIBOL, a programming language combining features of BASIC, FORTRAN and COBOL. COS also supported RPG

Implementations

The Commercial Operating System was implemented to run on hardware from the PDP-8 & PDP-11 family.

COS-310

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, VT-52 VDT, and a pair of eight inch floppy drives. Optionally you could purchase one or more 2.5 MB hard drives that had removable media. COS-310 was one of the operating systems available on the DECmate II.
Unlike under TSS-8, where each user had only a 4K virtual machine, on COS, each user had a virtual 32K.

COS-350

COS-350 was developed to support the PDP-11 Port of DIBOL, and was the focus for some vendors of turnkey software packages.
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. The much more powerful PDP-11/34 "added significant configuration flexibility and expansion capability."