Editing Digital Equipment Corporation (section)

=== PDP-6 and PDP-10 families (1963 and 1968) ===
{{Main|PDP-6|PDP-10}}

[[File:Locale_RS6_KA10 mod end.jpg|thumb|right|A "B" (blue) series Flip Chip module containing nine transistors, 1971]]

While the PDP-5 introduced a lower-cost line, 1963's [[PDP-6]] was intended to take DEC into the [[Mainframe computer|mainframe]] market with a [[36-bit computing|36-bit]] machine. However, the PDP-6 proved to be a "hard sell" with customers, as it offered few obvious advantages over similar machines from the better-established vendors like [[IBM]] or [[Honeywell]], in spite of its low cost around $300,000. Only 23 were sold,<ref name="miller457">Miller 1997, pg. 457</ref> or 26 depending on the source,<ref>{{cite web |date=January 30, 1998 |title=PDP-6 |url=http://research.microsoft.com/~gbell/Digital/timeline/1964-1.htm |access-date=September 6, 2022 |work=DIGITAL Computing Timeline}}</ref> and unlike other models the low sales meant the PDP-6 was not improved with successor versions. However, the PDP-6 is historically important as the platform that introduced "Monitor", an early [[time-sharing]] operating system that would evolve into the widely used [[TOPS-10]].<ref>{{cite web|url=http://www.bitsavers.org/pdf/dec/pdp6/PDP-6_TimsharingBroch.pdf |archive-url=https://web.archive.org/web/20040827060926/http://www.bitsavers.org/pdf/dec/pdp6/PDP-6_TimsharingBroch.pdf |archive-date=2004-08-27 |url-status=live|title=PDP-6 Timesharing Software|id=DEC Publication F-61B}}</ref>

When newer Flip Chip packaging allowed the PDP-6 to be re-implemented at a much lower cost, DEC took the opportunity to refine their 36-bit design, introducing the [[PDP-10]] in 1968. The PDP-10 was as much a success as the PDP-6 was a commercial failure; about 700 mainframe PDP-10s were sold before production ended in 1984.<ref name=miller457/> The PDP-10 was widely used in university settings, and thus was the basis of many advances in computing and [[operating system]] design during the 1970s. DEC later re-branded all of the models in the 36-bit series as the "DECsystem-10", and PDP-10s are generally referred to by the model of their CPU, starting with the "KA10", soon upgraded to the "KI10" (I:Integrated circuit); then to "KL10" (L:Large-scale integration [[Emitter-coupled logic|ECL logic]]); also the "KS10" (S: Small [[Form factor (design)|form factor]]). Unified product line upgrades produced the compatible [[DECSYSTEM-20]], along with a [[TOPS-20]] operating system that included [[virtual memory]] support.

The Jupiter Project was supposed to continue the mainframe product line into the future by using [[gate array]]s with an innovative Air Mover Cooling System, coupled with a built-in floating point processing engine called "FBOX". The design was intended for a top tier scientific computing niche, yet the critical performance measurement was based upon COBOL compilation which did not fully utilize the primary design features of Jupiter technology.{{citation needed|date=September 2015}} When the Jupiter Project was cancelled in 1983, some of the engineers adapted aspects of the 36-bit design into a forthcoming 32-bit design, releasing the high-end VAX8600 in 1985.