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The COS Operating System

Introduction

The COS-300 and COS-310 systems are of the same family and are similar. The latter sophisticated COS-310 system however, was initially designed for the small system user. Notwithstanding this, the COS-310 has expansion flexibility built into the system to accommodate the degree of complexity normally associated with the COS-300 system. The COS-310 system is streamlined for efficiency within its intended environment. Among other things, this means that some of the peripherals have been removed. Paper tape and card readers for example, are not available on COS-310. But, newer devices were introduced to the system. In particular, the RX8E Diskette came with the 310, as did the VT50H terminal.

The COS-310 was DEC's commercial operating system for the PDP-8. COS-310 was a derivative of MS/8 and OS/8, but with a new text file format. The file system is almost the same as OS/8, but dates are recorded differently and some applications can run under both COS and OS/8. The DIBOL language was the mainstay programming language of COS.

The minimum COS system hardware requirements are shown below:

COS-300 System

  • PDP-8/E Computer
  • Mass storage device
  • 16KB of core memory
  • User terminal
  • Line Printer

COS-310 System

  • PDP-8/A Computer
  • Two RX8E Dual Diskette Drives
  • 16KB of core memory
  • User terminal
  • Line Printer
Software Components

The following programs are provided as part of the COS operating system.

  • MONITOR/EDITOR Controls the calling and executing of all other programs in the COS system; provides the I/O control for the peripheral devices and an editing capability for correcting user programs. This program is referred to throughout the manual as Monitor.
  • SYSGEN - Specifies the system configuration and assigns logical device numbers for system startup.
  • COMP - Translates DIBOL language source statements into a binary object program which can be run on the COS 300 computer.
  • PIP - (Peripheral Interchange Program) transfers data, text files and binary files between two devices.
  • BUILD - Creates data files based on the contents of data fields typed by the user.
  • SORT - Sequences records according to key characters or fields specified by the user. Records may be sorted into ascending (0-9 or A-Z) or descending (Z-A or 9-0) sequence.
  • UPDATE - Performs maintenance on data files. UPDATE males the specified changes, created a new file and prints a report showing all changes, deletions and insertions.

Please refer to the Software Documentation page here for more information on CAPS-8.

DEC COS System Reference Manual

DEC COS300/310 System Reference Manual