Least PC-Compatible MS-DOS machines?

On Thu, Jun 5, 2014 at 10:43 PM, David Riley <fraveydank at gmail.com> wrote: When the Twiggy and 3.5" drive decisions were made, Apple most definitely did already have legions of fanatical acolytes, although obviously not as many as today. However, said acolytes were already accustomed to Apple using disk formats that were not interchangeable with anything else, and for the most part didn't care. There was a third party opportunity for add on products for compatibility. The Twiggy was being designed for use across Apple's entire product line well before the plans for the in-development Lisa started looking even vaguely similar to the Lisa that actually shipped. Apple knew that they needed higher-capacity floppies, and thought (incorrectly, as it turns out) that they could engineer and manufacture a better drive than they could buy, at lower cost. As such, there was no need for the disk format to match anyone else's. It was also not yet obvious to everyone that the PC would end up with >90% market share. Since Apple wasn't trying to build machines with capabilities comparable to the PC, but rather to far surpass it, they wouldn't have seen any value to spending a single additional cent of production cost on adding any form of PC compatibility. It's possible that if a PC-compatible floppy format that existed in 1982 met Apple's capacity and performance requirements, AND was less expensive to produce than their home-grown stuff, they might have been willing to use it. Or maybe not; they did have a significant amount of NIH mentality. Apple switched to the Sony 3.5 inch drive well before there was any solid evidence that it would become an industry standard, so there was still no particular need for Apple's 3.5 inch format to match anyone else's. IIRC the only contemporary (1983-ish) almost-PC-compatible machines using the Sony 3.5 inch drives did not actually use the later 720K standard format, so even if Apple had used MFM rather than Woz GCR, it still wouldn't likely have been compatible with anything significant, unless IBM had later deliberately chosen to be compatible with Apple, which would have been unlikely. While the Twiggy turned out to be a fiasco, I don't think that the general idea of using an incompatible disk format was actually a mistake.at the time.