Parallel Element Processing Ensemble: Difference between revisions

Revision as of 16:48, 1 June 2022

Revision as of 17:21, 1 February 2024

Line 1:

The '''Parallel Element Processing Ensemble''' ('''PEPE''') was one of the very early [[parallel computing]] systems. Bell began researching the concept in the mid-1960s as a way to provide high-performance computing support for the needs of [[anti-ballistic missile]] (ABM) systems. The goal was to build a computer system that could simultaneously track hundreds of incoming [[ballistic missile]] [[warhead]]s.<ref name=silogic>[http://www.silogic.com/PEPE/PEPE.html PEPE - Parallel Element Processing Ensemble] Last updated on June 8, 2011.</ref><ref name=Ford>{{cite book|author=R. Michael Ford|title=Parallel supercomputing in SIMD architecture|edition=1st|publisher=CRC Press|year=1990|page=[https://archive.org/details/parallelsupercom00hord/page/7 7]|isbn=0-8493-4271-6|url-access=registration|url=https://archive.org/details/parallelsupercom00hord/page/7}}</ref><ref>[https://web.archive.org/web/20130408132455/http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=AD0911667 Real-Time Advanced Data Processing Parallel Element Processing Ensemble (PEPE)], June 30, 1973, Final Report for Contract DAHC60-72-C-0031, prepared by the System Development Corporation of Huntsville, Alabama for the U.S. Army Advanced Ballistic Missile Defense Agency.</ref> A single PEPE system was built by [[Burroughs Corporation]] in the 1970s, by which time the [[US Army]]'s ABM efforts were winding down. The design later evolved into the [[Burroughs Scientific Computer]] for commercial sales, but a lack of sales prospects led to it being withdrawn from the market.

PEPE came about as a result of predictions of the sorts of [[ICBM]] forces that would be expected in the event of an all-out Soviet attack during the 1970s. Missile fleets of both the US and USSR were growing through the 1960s, but a bigger issue was the rapid increase in the number of warheads as a result of the move to [[multiple independently targetable reentry vehicle]]s (MIRV). Computers designed for the [[Nike-X]] system were largely similar to systems like the [[IBM 7030]], and would have been able to handle attacks withof perhaps a dozen warheads arriving simultaneously. With MIRV, hundreds of targets, both warheads and decoys, would arrive at the same time, and the CPUs being used simply did not have the performance needed to analyze their trajectories quickly enough to leave time to attack them.<ref name=silogic/>

An initial testbed system, the "IC model", was built with 16 processors consisting of individual [[integrated circuit]]s and connected to an [[IBM 360]]/65 host. This proved successful, and in the early 1970s, Burroughs won the contract to build a prototype of the full-sized 288-processor version in the early 1970s. The design featured an array of 288 (8 × 36) array of identical processing elements and [[Content-addressable memory|associative addressing]]. EachThe processingelements elementconsisted containedof athree minimummain of[[Execution controlunit|functional logicunits]], the bulk of the control being concentrated in a common[[floating controlpoint unit.processor]] Thethat controlcould unitperform readbasic instructionsarithmatic fromincluding memory, decodedsquare themroots, and issuedseparate theminput toand alloutput processingaddress elementsgenerators simultaneouslythat socould thatdetermine the elementsassociative wereaddress requiredof tothe executenext exactlydata theelement sameto instructionbe atread, exactlyand the sameaddress time.of Thethe elementsoutput weresuch capablethat ofthe executingresults awere completeordered singleacross addressprocessors.<ref instructionname=pepebline>{{cite repertoiremagazine permitting|url=http://www.silogic.com/PEPE/PEPE.html any|title=PEPE desired|magazine= arithmeticBurroughs orB-Line logical|date=July operation.1977}}</ref>

Each processing element contained a minimum of control logic, the bulk of the control being concentrated in a common control unit. The control unit read instructions from memory, decoded them, and issued them to all processing elements simultaneously so that the elements were required to execute the same instruction at the same time. The elements were capable of executing a complete single address instruction including reading and writing the data.<ref name=silogic/>

A [[Burroughs B1700]] computer system was used as a test and diagnostic computer. A custom software package, called TRANSET, which executed on the B1700 was used to debug and maintain PEPE's processing elements. Burroughs delivered PEPE to the Ballistic Missile Defense Advanced Technology Center (part of US Army's Strategic Defense Command) in [[Huntsville, Alabama]] in 1976.<ref name=silogic/><ref name=Ford/> Testing was apparently successful, but Bell concluded that the machine was too expensive for the sorts of threats being faced by the [[Safeguard Program]] that was being deployed in the 1970s.

A [[Burroughs B1700]] computer system was used as a test and diagnostic computer. A custom software package, called TRANSET, which executed on the B1700 was used to debug and maintain PEPE's processing elements. Burroughs delivered PEPE to the Ballistic Missile Defense Advanced Technology Center (part of US Army's Strategic Defense Command) in [[Huntsville, Alabama]] in 1976.<ref name=silogic/><ref name=Ford/> Testing was apparently successful, but Bell concluded that the machine was too expensive for the sorts of threats being facedaddressed by the [[Safeguard Program]] that was being deployed in the 1970s.<ref name=silogic/>

==References==