>>The 68000 hardware could support preemptive multitasking just fine; what it lacked was a hardware MMU.
Yes, exactly. Thanks for clarifying. As you say, the lack of preemptive multitasking was mainly an OS limitation, although a hardware MMU would have really helped. I remember at the time reading about the hoops that Andy had to go through to get Switcher (which, as mentioned in other replies, became MultiFinder) to work. One of the issues was that the single app OS model used a bunch of low memory locations as system globals...on every context switch these had to be saved and restored because each running application could change them. (ouch!)
Yes, exactly. Thanks for clarifying. As you say, the lack of preemptive multitasking was mainly an OS limitation, although a hardware MMU would have really helped. I remember at the time reading about the hoops that Andy had to go through to get Switcher (which, as mentioned in other replies, became MultiFinder) to work. One of the issues was that the single app OS model used a bunch of low memory locations as system globals...on every context switch these had to be saved and restored because each running application could change them. (ouch!)