The Multics Input/Output system

ABSTRACT

An I/0 system has been implemented in the Multics system that facilitates dynamic switching of I/0 devices. This switching is accomplished by providing a general interface for all I/O devices that allows all equivalent operations on different devices to be expressed in the same way. Also particular devices are referenced by symbolic names and the binding of names to devices can be dynamically modified. Available I/0 operations range from a set of basic I/0 calls that require almost no knowledge of the I/O System or the I/0 device being used to fully general calls that permit one to take full advantage of all features of an I/O device but require considerable knowledge of the I/0 System and the device. The I/O System is described and some popular applications of it, illustrating these features, are presented.

REFERENCES

• 1: Daley, R.C. and Neumann, P.G., "A General-Purpose File System for Secondary Storage", AFIPS, 1965 Fall Joint Computer Conference, Vol. 27, Part I, Spartan Books, Washington, D.C., pp. 213-229.
• 2: J. H. Saltzer, TRAFFIC CONTROL IN A MULTIPLEXED COMPUTER, Massachusetts Institute of Technology, Cambridge, MA, 1966
• 3: Lett, A. and Konigsford, W., "TSS/360: A Time-Shared Operating System", AFIPS, 1968 Fall Joint Computer Conference, Vol. 33, Part I, MDI Publications, Wayne, Pennsylvania, pp. 15-28.
• 4: CP-67/CMS User's Guide, IBM, October, 1970.
• 5: #System/360 Operating System Concepts and Facilities, IBM, Form 128-6535-1, June, 1967.
• 6: Ossanna, J.F., Mikus, L., and Dunten, S., "Communications and Input-Output Switching in a Multiplex Computing System", AFIPS, 1965 Fall Joint Computer Conference, Vol. 27, Part 1, Spartan Books, Washington, D.C., pp. 231-242.
• 7: Multics Programmers' Manual, Preliminary Edition, M.I.T., April, 1971.

INDEX TERMS

Primary Classification:
  D. Software
  D.4 OPERATING SYSTEMS
      D.4.0 General

          Nouns: MULTICS

Additional Classification:
  B. Hardware
  B.4 INPUT/OUTPUT AND DATA COMMUNICATIONS
      B.4.2 Input/Output Devices

General Terms:
Management