IMP/TIP memory retrofit schedule
A schedule for upgrading the network's IMP and TIP memory
McKenzie, A.M., "IMP/TIP memory retrofit schedule", RFC 447, DOI 10.17487/RFC0447, January 1973, <https://www.rfc-editor.org/info/rfc447>.
@misc{rfc447,
series = {Request for Comments},
number = 447,
howpublished = {RFC 447},
publisher = {RFC Editor},
doi = {10.17487/RFC0447},
url = {https://www.rfc-editor.org/info/rfc447},
author = {A.M. McKenzie},
title = {{IMP/TIP memory retrofit schedule}},
pagetotal = 2,
year = 1973,
month = jan,
} RFC text
Network Working Group Alex A. McKenzie
RFC # 447 BBN-NET
NIC # 14104 January 29, 1973
Updates: 434
IMP/TIP Memory Retrofit Schedule (Revision 1)
This revision contains two major changes to RFC #434. First, all
retrofits scheduled prior to February first have been completed and are
therefore removed from the schedule. Second, the CCA retrofit has been
rescheduled from 3/20 to 2/28.
The revised text of RFC # 434 follows:
During the first several month of 1973 we will be retrofitting each IMP
and TIP with additional core memory. At the end of the retrofit
program, the memory sizes of the various machines will be as follows:
IMP (516 or 316) - 16K words
TIP - 28K words
TIP with Magnetic Tape Option - 32K words
In addition, the expansion of the TIP core memory will necessitate
enlarging the TIP to two cabinets.
Listed below is the schedule for the remaining retrofits. We have
arranged this schedule to coincide with usual monthly Preventive
Maintenance at each site so as to minimize user inconvenience, but the
work required will frequently require the machines to be down longer
than normal. I will issue additional RFC's updating this schedule as
necessary.
Any site which anticipates difficulty with the expansion of TIP size,
and thus the floor space requirement, should contact Hawley Rising (BBN)
at
(617) 491-1850 ext. 473
All dates given below are in the form (month/day)
Utah (2/1)
UCSB (2/6)
Belvoir (2/8)
NOAA (2/12)
USC (2/13)
Stanford (2/14)
ETAC (2/15)
Aberdeen (2/22)
ISI (2/22)
Case (2/26)
CCA (2/28)
SRI (3/7)
Rome (3/14)
FNWC (3/15)
UCLA (3/19)
AMES IMP (3/21)
GWC (3/22)
Carnegie (4/4)
SDC (4/17)
Illinois (4/18)
[ This RFC was put into machine readable form for entry ]
[ into the online RFC archives by Alex McKenzie with ]
[ support from GTE, formerly BBN Corp. 9/99 ]
AI ELI5
On this page
§1Memory Retrofit Program
In early 1973, BBN began retrofitting the IMP (Interface Message Processor) and TIP (Terminal Interface Processor) computers that routed traffic on the ARPANET. The goal was to give each machine more memory: IMPs would gain 16K words of core memory, and TIPs would gain 28K words (or 32K with the magnetic tape option).
The RFC is an update to RFC 434, announcing that completed retrofits had been removed from the schedule and one site's date had moved earlier.
The early network's computers needed a memory upgrade. This note updates which dates they were being swapped out.
§2The Retrofit Schedule
The schedule coordinated with each site's regular monthly preventive maintenance to minimize user disruption, though machines would be down longer than usual during the retrofit. The retrofits ran from February through April 1973, touching about 18 major network sites.
Sites affected included universities (Stanford, MIT, Utah, UCLA), research centers (SRI, ISI, RAND), and government installations (Belvoir, NOAA). BBN asked sites anticipating floor space problems (since the TIP would expand to two cabinets) to contact Hawley Rising for assistance.
Each network site got a date when its computers would be upgraded. The work was scheduled during maintenance windows to avoid disrupting users too much.
§3Status
RFC 447 is Historic and was replaced by RFC 476. The retrofit program itself finished in 1973, and the memory expansions it described became standard for those machines for years afterward.
This was just a planning document for a 1973 hardware upgrade. The project finished long ago.