The Apple IIGS megahertz myth

A story you hear all the time about the Apple IIGS is that Apple purposefully underclocked or limited its processor in some way to protect the nascent Macintosh, and ensure the IIGS, which could build upon the vast installed base of Apple II computers, would not outcompete the Macintosh. I, too, have always assumed this was a real story – or at least, a story with a solid kernel of truth – but Dan Vincent decided to actually properly research this claim, and his findings tell an entirely different story.

His research is excellent – and must have been incredibly time-consuming – and his findings paint a much different story than Apple intentionally holding the IIGS back. The actual issue lied with the production of the 65816 processor that formed the beating heart of the IIGS. It turns out that the 65816 had serious problems with yields, was incredibly difficult to scale, and had a ton of bugs and issues when running at higher speeds.

What a ride, huh? Thanks for making it this far down a fifty-plus minute rabbit hole. I can’t claim that this is the final take on the subject—so many of the players aren’t on the record, but I’m pretty confident in saying that Apple did not artificially limit the IIGS’ clock speed during its development for marketing purposes. Now, I’m not a fool—I know Apple didn’t push the IIGS as hard as it could, and it was very much neglected towards the end of its run. If the REP/SEP flaws hadn’t existed and GTE could’ve shipped stable 4MHz chips in volume, I’m sure Apple would’ve clocked them as fast as possible in 1986.
↫ Dan Vincent

Promise me you’ll read this article before the weekend’s over. It’s a long one, but it’s well-written and a joy to read. You’ll also run into Tony Fadell – the creator of the iPod – somewhere in the story, as well as a public shouting match, and an almost fistfight, between the creator of the 65816 and Jean-Louis Gassée during San Francisco AppleFest in September 1989, right after Gassée placed the blame for the lack of a faster IIGS on the 65816’s design.

This is an evergreen article.