Comment by CharlesW
3 days ago
Jobs mischaracterized the innovation, and the author is technically correct (the best kind), but it's a shame that the piece appears to want to bury Holt's actual accomplishment. Holt's work was innovative in the same way that Woz's Disk II controller was. He didn’t invent the underlying technology, and he did create an elegant, product-defining implementation of a known (but difficult) technique.
Author here. Can you clarify what you consider Holt's innovative power supply accomplishment to be? I spent an excessive amount of time studying Holt's power supply to find out what made it special, but couldn't find anything particularly important.
Yeah it's nothing special. I find the whole Apple innovation thing quite tedious if I'm honest. I've seen some milspec stuff from around that era that purposely misused an LM723 as an SMPS. This was done without any fanfare at all even though it was quite interesting.
I wouldn't put Holt's power supply on the same pedestal as the Woz drive controller which I feel was actually innovative but perhaps what the angle they are looking at is just the apparent dearth of switched mode power supplies in the market for home computers, games etc at that time. If I think back to that time, Atari, Commodore, Radio Shack, TI etc - they all used heavy transformer bricks and linear regulators. I think the BBC microcomputer went to an Astec switch mode supply after a brick on launch and that was in 1982. Maybe it was this rise of Astec that you can somehow attribute to Apple and Rod Holt after a fashion.
I second your analysis, there's nothing special at all about it. By the standards of the time it was a unusual to see a switch-mode supply in a computer, but the supply itself isn't unique when compared to contemporary designs. Mix "unusual application of a known technology" with "Apple fanboyism" and you get "Holt revolutionized power supplies" or whatever the claim is.