you are correct, the Exec micro kernel was fully preemptive, or as much as it could be without the benefit of an MMU. Message passing through pointer exchange,

you are correct, the Exec micro kernel was fully preemptive, or as much as it could be without the benefit of an MMU. Message passing through pointer exchange, no protection context,, etc. not pretty but it made for usable multitasking in a paltry 512k of memory at 7.16mhz.