Question

The master PIC 8259A decides which of its slave interrupt controllers is to return the vector address, as a response of

(a) first INTA (active low) pulse from 80286

(b) second INTA (active low) pulse from 80286

(c) third INTA (active low) pulse from 80286

(d) none of the mentioned

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Answer 1

Right option is (a) first INTA (active low) pulse from 80286

Easiest explanation: In response to the first INTA (active low) pulse from 80286, the master PIC 8259A decides, which of its slave interrupt controllers is to return the vector address.