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Some historic moments in networking (RFC0089)

IP.com Disclosure Number: IPCOM000006050D
Original Publication Date: 1971-Jan-19
Included in the Prior Art Database: 2001-Nov-29
Document File: 8 page(s) / 17K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

R.M. Metcalfe: AUTHOR

Abstract

While awaiting the completion of an interim network control program (INCP) for the MIT MAC Dynamic Modeling/Computer Graphics PDP-6/10 System (MITDG), we were able to achieve a number of 'historic moments in networking' worthy of some comment. First, we were able to connect an MITDG terminal to a Multics process making it a Multics terminal. Second, we successfully attached an MITDG terminal to the Harvard PDP-10 System thereby enabling automatic remote use of the Harvard System for MIT. Third, we developed primitive mechanisms through which remotely generated programs and data could be transmitted to our system, executed, and returned. Using these mechanisms in close cooperation with Harvard, we received graphics programs and 3D data from Harvard's PDP-10, processed them repeatedly using our Evans & Sutherland Line Drawing System (the E&S), and transmitted 2D scope data to Harvard's PDP-1 for display.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 21% of the total text.

Network Working Group                                        B. Metcalff

Request for Comments: 89                                           MITDG

NIC: 5697                                                19 January 1971

                  SOME HISTORIC MOMENTS IN NETWORKING

   While awaiting the completion of an interim network control program

   (INCP) for the MIT MAC Dynamic Modeling/Computer Graphics PDP-6/10

   System (MITDG), we were able to achieve a number of 'historic moments

   in networking' worthy of some comment.  First, we were able to

   connect an MITDG terminal to a Multics process making it a Multics

   terminal.  Second, we successfully attached an MITDG terminal to the

   Harvard PDP-10 System thereby enabling automatic remote use of the

   Harvard System for MIT.  Third, we developed primitive mechanisms

   through which remotely generated programs and data could be

   transmitted to our system, executed, and returned.  Using these

   mechanisms in close cooperation with Harvard, we received graphics

   programs and 3D data from Harvard's PDP-10, processed them repeatedly

   using our Evans & Sutherland Line Drawing System (the E&S), and

   transmitted 2D scope data to Harvard's PDP-1 for display.

The IINCP

   Our experiments were run on the MITDG PDP-6/10 using what we have

   affectionately called our 'interim interim NCP' (IINCP).  Under the

   IINCP the IMP Interface is treated as a single-user I/O device which

   deals in raw network messages.  The software supporting necessary

   system calls includes little more than the basic interrupt-handling

   and buffering schemes to be used later by the NCP.  In short, the

   user-level programs which brought us to our historic moments were

   written close to the hardware with full knowledge of IMP-HOST

   Protocol (BBN 1822).  When the INCP and NCP are completed, these

   programs can be pruned considerably (80%).  The exercise of writing

   programs which conform to IMP-HOST Protocol was not at all wasted.

   Only now can those of us who are not writing the NCP begin to grasp

   the full meaning of RFNM's and their use in flow control.  The

   penalties for ignoring an impatient IMP, for failing to send NOOPS

   (NO-OPS) when starting up, and for blasting data onto the Network

   without regard for RFNM's are now well understood.

The Multics Connection

   Our quest for historic moments began with the need to demonstrate

   that the complex hardware-software system separating MITDG and

   Multics was operative and understood.  A task force (Messrs. Bingham,

Metcalff                                                        [Page 1]

RFC 89            SOME HISTORIC MOMENTS IN NETWORKING    19 January 1971

   Brodie, Knight, Metcalfe, Meyer, Padlipsky and Skinner) was

   commissioned to establish a 'polite conversation' between a Multics

   terminal and an MITDG terminal.

   It was agreed that messages would be what we call 'network ASCII

   messages': 7-bit ASCII characters right-adjusted in 8-bit fields

   having the most significant bit set, marking, and padding.  In that

   Multics is presently predisposed toward line-oriented half-duplex

   terminals, it was decided that all transmissions would end with the

   Multics EOL character (ASCII <LINE FEED>).  To avoid duplicating much

   of the INCP in our experiment, the PDP-10 sid...