The result was predictable. The customers didn't want to throw out their old software; the computer could only use its snazzy new feature if they did. So all those computers ended up just never using the snazzy new feature. They ran in real mode all the time, running the old DOS software just like it ran on the original PC, just slightly faster.
Which was kind of a buzzkill when you'd paid thousands of dollars more for the shiny new PC/AT than you would have if you'd just bought a clone of the original PC.
All the big projects that had been launched to take advantage of the 286's protected mode ran head-first into this barrier. The OS/2 project floundered as IBM and Microsoft tried to figure out how to cope with it. Microsoft wanted to just skip over the 286 altogether and make OS/2 require Intel's upcoming successor chip, the 80386, which was supposed to remove the boneheaded "you can check into protected mode, but you can never leave" limitation. But IBM had sold a massive pile of 286-based PC/AT machines to its customers on the promise that OS/2 would run on them. From IBM's perspective, OS/2 HAD to be made to work on the 286, no matter how bad the 286 was -- because otherwise they'd have the entire Fortune 500 screaming at them about false marketing.
This opened up a fundamental rift between IBM and Microsoft which would doom the OS/2 project. Believing that no multitasking OS could ever be made to work on the 286, Microsoft secretly began working on its own successor-to-DOS project, called "Windows."
While Windows 1.0 was targeted to the old 8088 processor, by 2.0 they were offering a "Windows/386" version that was targeted at Intel's new chip. They offered a "Windows/286" version of Windows 2.0 as well, but it didn't even try to use the chip's protected mode. It just treated it like a slightly faster 8088 with a few modest extra features.
This opened up a fundamental rift between IBM and Microsoft which would doom the OS/2 project. Believing that no multitasking OS could ever be made to work on the 286, Microsoft secretly began working on its own successor-to-DOS project, called "Windows."
While Windows 1.0 was targeted to the old 8088 processor, by 2.0 they were offering a "Windows/386" version that was targeted at Intel's new chip. They offered a "Windows/286" version of Windows 2.0 as well, but it didn't even try to use the chip's...