ISTM that if Microsoft had managed to add preemptive multitasking to Windows 3.x in a backward-compatible way, this would've given us as close to an Amiga-like OS as one could ever hope to run on 8086 and 286 hardware. Perhaps even more so, if hardware could be expected to have multimedia capabilities as a standard, without relying on 3rd-party drivers - PC had this on the PCjr, and later Tandy.
> ISTM that if Microsoft had managed to add preemptive multitasking to Windows 3.x in a backward-compatible way, this would've given us as close to an Amiga-like OS as one could ever hope to run on 8086 and 286 hardware.
8086 didn't have the instruction set to do preemptive, and the 286's memory model was 64kb pages... and barely good enough. The enabler for MPC (Multimedia PC) was the combination of 386 (and 386sx) + 16 bit sound card + CDROM + PCI VGA+.
Just for accuracy: Win3.x had pre-emptive multitasking. However, it could only preempt DOS apps. Win16 apps could not be pre-empted.
This compares quite closely to the FOSS RISC OS for Arm machines, which can preempt CLI apps in a "task window", but GUI apps only multitask cooperatively.
Co-op multitasking is faster and more memory efficient. That's why Acorn and MS chose it. But it's very vulnerable to a single app failing to relinquish control, locking up the OS.
