Gregory's Server
But it could be worse. The Intel iAPX 432 (1981) was supposed to be Intel's main processor. It had instructions from 6 to 321 *bits* in length so instructions weren't even byte aligned. The iAPX 432 was too complicated, went way over schedule, and was a commercial failure.
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6 comments
Simplicity was what I liked about the PDP-8. But then, there are limits what you can do with a 12-bit instruction size, 12-bit bus width, ...  @kenshirriff Holy shit that was ambitious https://en.wikipedia.org/wiki/Intel_iAPX_432#Architecture  @kenshirriff I worked on computers with many different architectures in this time period, but never saw one based upon the iAPX 432. It seemed like most of even the ideas of this processor were judged to be architectural dead ends, and there were essentially no spiritual successors of any note. Am I wrong?
[DATA EXPUNGED]
 @kenshirriff This is the paper that sank the iAPX 432. It was demonstrably slower than the 8086 it was supposed to replace. I'm *really* curious to know if there's a working copy of the '432 in existence today. Have you come across one? https://archive.org/details/PerformanceEvaluationOfTheIntelAPX432 |
For more details, see my blog post: https://www.righto.com/2023/02/how-8086-processor-determines-length-of.html
Credit: die photo of the iAPX 432 is from Intel and the Computer History Museum. https://www.computerhistory.org/collections/catalog/102652367