Page 101 -

I/O program 4 I/O command Interrupt handler 5 END

(c) Interrupts; long I/O wait

User program 1 WRITE 2 WRITE 3 WRITE

I/O program 4 I/O command Interrupt handler 5 END

(b) Interrupts; short I/O wait

User program 1 WRITE 2a 2b WRITE 3a 3b WRITE

program Program Flow of Control without and with Interrupts
I/O 4 I/O command 5 END

(a) No interrupts

User program 1 WRITE 2 WRITE 3 WRITE Figure 3.7

75