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Bolt, Beranek and Newman - IMP

Manufacturer Bolt, Beranek and Newman, of Cambridge, MA.
Identification,ID Interface Message Processor (IMP)
Date of first manufacture-
Number produced -
Estimated price or cost-
location in museum -
donor -

Contents of this page:

Interface Message Processor (IMP) ,
ARPANET as of Nov 1970 (300 K Bytes)



Special features

Historical Notes
Russell Ham kindly informed (May 26, 2001)
... ARPA Interface Message Processor, ... the manufacturer, who was Bolt, Beranek and Newman, of Cambridge, MA.

Richard Bolt and Leo Beranek were affiliated (in a relationship which others can document better than I) with M.I.T., where a large chunk of ARPAnet evolution took place.(I can't recall Newman at the moment.)

BBN (which seems for some silly reason to have decided recently to disguise itself as "Genuity") was originally a consultant firm in acoustical engineering, but heavily staffed by computer-savvy folks who came to be the core of the company. ('' is a significant hunk of the backbone of today's internet.)

This Artifact

Interesting Web Sites

Other information
From the back page of CORE 3.1

From the Collection of

Explained from CORE 2.3

The Interface Message Processor (IMP) as the packet switching node of the ARPANET, which connected computer systems, beginning in the early 19705. Into a nationwide research network for computer resource sharing. This ARLAN ET originally consisted of only four nodes (UCLA, SRI, UCSB, and the University of Utah) and eventually grew to over 100 nodes. It was connected via "gateways" (now called routers) to two other networks (packet radio and SATNET) that were also supported by DARPA (Defense Advanced Research Projects Agency). These three interconnected networks ultimately evolved into today's Internet with its tens of millions of nodes.

During an early ARPANET planning engineer Wesley Clark suggested developing a standard computer interface in order to avoid creating separate hardware and software for every different time Sharing System that would be connected. The IMP was thus a communications switch" accepting packets and relaying them to other IMPS or locally connected host computers. In December 1968,

DARPA selected Bolt Beranek and Newman (BBN) to develop the IMP. Frank Heart led the team, with Severo Ornstern as lead hardware developer and Bill Crowther as lead programmer. MIT professor Bob Kahn, who had taken a leave of absence in 1966 to join BBN, was responsible for the system design.

Shortly before the planned delivery date of September 1, 1969, the first IMP arrived at the laboratory of Professor Len Kleinrock at UCLA. A month later, the second IMP arrived at SRI and, soon thereafter, the first characters were transmitted between SRI and UCLA. In November and December, IMPS number three and four were Installed at University of California Santa Barbara and the University of Utah. The network quietly expanded to 13 sites by January 1971 and 23 by April 1972.

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Updated March 22, 2002