13.3|The 8086 and 8089 in a Tightly Coupled Con guration
e 8086 directly supports multiprocessing also with processors called ‘independent processors’.
One such processor is the 8089 I/O processor. It is a processor specially designed by Intel to
handle input/output processing including DMA (Ref. Section. 11.5). is processor is inde-
pendent in the sense that it is not directed or dependant on the host processor. In a ‘local’ con-
fi guration, both the processors’ address, data and control signal lines are tied together. e only
way of communication between the two is by messages stored in their shared memor ...
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