The story of the first microprocessor, one you may have heard, goes something like this: The Intel 4004 was introduced in late 1971, for use in a calculator. It was a combination of four chips, and it could be programmed to do other things too, like run a cash register or a pinball game. Flexible and inexpensive, the 4004 propelled an entire industry forward; it was the conceptual forefather of the machine upon which you are probably reading this very article.

That’s the canonical sketch. But objects, events, people—they have alternate histories. Their stories can often be told a different way, from a different perspective, or a what could have been.

This is the story, then, of how another first microprocessor, a secret one, came to be—and of my own entwinement with it. The device was designed by a team at a company called Garrett AiResearch on a subcontract for Grumman, the aircraft manufacturer. It was larger, it was a combination of six chips, and it performed crucial functions for the F-14 Tomcat fighter jet, which celebrates the 50th anniversary of its first flight this week. It was called the Central Air Data Computer, and it computed things like altitude and Mach number; it figured out the angle of attack, key to landing and missile targeting; and it controlled the wing sweep, allowing the craft to be both maneuverable when the wings were at about 50 degrees and very, very fast when they were swept all the way back.

Ray Holt was one of the engineers for the Central Air Data Computer. He is probably not someone you have heard of—how could you have? He worked on the project, one of two people doing what’s called the logic design, for two years, between 1968 and 1970, with a team that included his younger brother, Bill. He couldn’t tell anyone about what they had built. The project was kept quiet by the Navy and by Garrett for decades as other engineers were awarded credit for inventing firsts. Later, when he was able to talk about the device, people were skeptical. //

The Intel engineers who share the title told the paper that the Central Air Data Computer was bulky, it was expensive, it wasn’t a general purpose device. One expert said it was not a microprocessor because of how the processing was distributed among the chips. Another—Russell Fish—said it was, noting, “The company that had this technology could have become Intel. It could have accelerated the microprocessor industry at the time by five years." But other people around that time also wanted to claim the title of father of the microprocessor; there were some big patent fights, and not everyone even agrees on the exact definition of a microprocessor in the first place.

“The discussion,” says Fish, who today runs an IP licensing company called Venray, “is not a technical one, it is a philosophical one.” Fish at one point wrote that the 4-bit 4004 could “count to 16,” while the 20-bit CADC “was evaluating sixth order polynomial expressions rapidly enough to move the control surfaces of a dogfighting swing-wing supersonic fighter.” When I spoke to him recently, he said he had gone back and read through the documentation. “What Ray Holt did was absolutely brilliant,” he says. “Particularly given the timeframe. Ray was generations ahead, algorithmically and computationally.”