Re: A85: Ram OS-new OS for 85
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Re: A85: Ram OS-new OS for 85
On Sun, 10 Aug 1997 Jonathan Anderson <sarlok@geocities.com> writes:
>As far as multitasking, preemptive multitasking (where the shell
>switches when it wants) would be impossible if you could not determine
>the program counter,
You can! Whenever an interrupt occurs (the only time you would get
a chance to switch tasks preemptively), the program counder is stored
on the stack!
However, the whole preemptive multitasking idea is wrecked whenever
a program disables interrupts, sets the interrupt mode back to 1, or
changes the I register to its own interrupt code...
--
Patrick Davidson (ariwsi@juno.com)
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http://www.calweb.com/~kwdavids/patrick/
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