CompuServe Messages

The Macintosh uses a cooperative system to appear to run multiple programs simultaneously. The Amiga uses a preemptive system to appear to run multiple programs simultaneously. By the usual(i.e., academic courses in OS design), only the latter counts as “true'' multitasking. But from the user's point of view, they are roughly equivalent. True, cooperative multitasking results in a less responsive system (you can't run an I/O-bound process at high priority while leaving most of the CPU to the compute-bound processes), and it tends to collapse in the presence of non-conforming programs (a single poorly-written program can lock out all other processes), but to call it nothing more than a task-switcher is misleading and incorrect.