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3.4.3
CONNECTING THE INTERRUPT LINES
North Star HSIO-4
The HSIO-4 board provides access to ten S-100
bus interrupt lines. These can cause eight
vectored interrupts (VIO - VI7), a
non-vectored interrupt (PINT), and a
non-maskable interrupt (NMI).
Each port provides four sources of interrupt.
The four interrupt sources from each port are
combined into a single interrupt source for
each port. These combined interrupt sources
—
one for each port —
Interrupt Header. As shown in Figure 3-25, the
interrupt sources for ports A, B, C, and D are
made available on pins 1, 2, 3, and 4,
respectively.
Any one or more of these combined interrupt
sources can be connected to an S-100 interrupt
line at the Interrupt Header.
connections to be made are determined by the
particular software in use; consult the manual
for the software you intend to use. If you are
writing your own software, it is recommended
that you utilize the standard Interrupt Header
wiring with which the HSIO-4 is supplied.
This wiring is illustrated in Figure 3-27.
54
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Figure 3-25
The specific
User/Technical Manual
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