The rise and fall of IBM's 4 Pi aerospace computers: an illustrated history

Amazing article. What really stands out for me besides the obviously interesting electronics details is the incredible mechanical engineering. Quite a few of the frames and frame components look as if they've been milled out of aluminum billets.

In the 70's I bought a 300A 5V IBM power supply for parts, it took a couple of hours to get it home and lug it up to my attic where I spent a few weeks disassembling it and I came away with the same impression: that thing was engineered in a way that I had not yet seen in other electronics gear that I had come across. It got me a lifetime supply of RCA 2N3055's, (the good ones, the Motorola ones were junk in comparison) as well as all manner of capacitors (sizes 'large' and 'gigantic').

IBM really knew how to engineer hardware.

This triggered a tangential memory of encountering this kind of aerospace computer box.

I was a teenage intern at a very serious software engineering company, which was doing bespoke high-end in-circuit emulators, integrated into a full-lifecycle software engineering platform.

One time I wandered into the hardware engineering area, there was a customer box looking a bit like the later-model photos in the article, just sitting on an EE bench. (Though my vague memory is that it might've been something like Honeywell or Rockwell?)

As a teen, with so may things to learn about workstation networks and software engineering, and working professionally for the first time, and becoming an adult... It was awhile before I slowly learned who were the customers for all this platform the company developed. It was for people who make complex, critical systems -- mainly military, aerospace, and datacommunications. So it was just further overwhelming wonder: people use our stuff for aircraft and spacecraft?! So cool!

Later in my career, I have more context, to decide the kinds of things I want to work on. I'm also often involved when we start with the understanding of the customer, and the building cool stuff tends to follow that. Some of the AI toys recently elicit some of that earlier wow of everything being new and cool, but now knowing more context, and seeing through some of the current marketing noise.

Author here: I've finally finished a detailed history of IBM's 4 Pi computers, powering everything from the B-1 bomber to the Space Shuttle. Let me know if you have questions...

About 360 and pi: In the late 70's, "Two Pi Corporation" of Santa Clara made S/370-clone minicomputers named V/32. In early 1981, Two Pi was acquired by Four Phase Systems of Cupertino, a maker of early PMOS cpus. Four Phase was itself acquired in late 1981 by Motorola and withered away. Four Phase's campus was leveled and replaced by Apple's Infinite Loop campus, with nearly the same footprint.

Cool stuff. Worked next to these one summer at IBM on dev tools that ran on PC. But never knew much about them. They were in the thick aluminum case and you didn't touch them!

I don't know how to put it into words, but this aesthetic of computers just looks sooo good. Makes me want to try making my homelab/experimental hardware look like it. Any ideas how to source parts that look similar in low quantities?

Back when I was in the USAF they told us 4 Pi was because it was essentially two IBM 360 mainframes in parallel. Probably BS but that was what we all thought.

Really happy to see this history lesson in any case, I had mostly forgotten about my experiences from the mid 90s.