Editing Data General Nova (section)

===Edson de Castro and the PDP-X===
[[Edson de Castro]] was the Product Manager of the pioneering [[Digital Equipment Corporation]] (DEC) [[PDP-8]], a 12-bit computer widely referred to as the first true minicomputer.<ref>{{cite book |url=https://books.google.com/books?id=NrMkBQAAQBAJ&pg=PA165 |title=The Computing Universe: A Journey through a Revolution |first1=Tony |last1=Hey |first2=Anthony |last2=Hey |first3=Gyuri |last3=Pápay |date=2014 |page=165 |publisher=Cambridge University Press |isbn=9780521766456}}</ref> He also led the design of the upgraded PDP-8/I, which used early [[integrated circuit]]s in place of individual transistors.{{sfn|Hendrie|2002|p=40}}

During the PDP-8/I process, de Castro had been visiting [[printed circuit board|circuit board]] manufacturers who were making rapid advances in the complexity of the boards they could assemble. de Castro concluded that the 8/I could be produced using fully automated assembly on large boards, which would have been impossible only a year earlier. Others within DEC had become used to the smaller boards used in earlier machines and were concerned about tracking down problems when there were many components on a single board.{{efn|This was likely a reaction to the problems with the [[PDP-6]], which used large boards and had significant failure rates. The [[PDP-10]], essentially a re-engineered PDP-6, uses smaller "flip-chip" cards.}} For the 8/I, the decision was made to stay with small boards, using the new "[[Flip-Chip module|flip-chip]]" packaging for a modest improvement in density.{{sfn|Hendrie|2002|p=40}}

During the period when the PDP-8 was being developed, the introduction of [[ASCII]] and its major update in 1967 led to a new generation of designs with word lengths that were multiples of 8 bits rather than multiples of 6 bits as in most previous designs. This led to mid-range designs working at 16-bit word lengths instead of DEC's current 12- and 18-bit lineups. de Castro was convinced that it was possible to improve upon the PDP-8 by building a 16-bit minicomputer CPU on a single 15-inch square board.{{sfn|Supnik|2004}}{{sfn|Hendrie|2002|p=48}}

In 1967, de Castro began a new design effort known as "PDP-X" which included several advanced features. Among these was a single underlying design that could be used to build 8-, 16-, and 32-bit platforms.{{sfn|Hendrie|2002|p=42}} This progressed to the point of producing several detailed architecture documents. [[Ken Olsen]] was not supportive of this project, feeling it did not offer sufficient advantages over the 12-bit PDP-8 and the 18-bit [[PDP-9]]. It was eventually canceled in the spring of 1968.{{sfn|Supnik|2004}}