Impulse 4030 - Manual (Page 7)

© Sealevel Systems, Inc. - 5 - PIO-48 User Manual
Wait States
The PIO-48 has the option of inserting one 500 nS wait state for each access. This
may be required on certain machines with bus clocks in excess of 8 MHz. With the
wide variety of machines available, no concrete rules exist concerning wait states. If
the PIO-48 doesn't seem to be responding properly, try inserting a wait state.
To enable wait state insertion, set position 8 of the dip-switch to "ON". To disable
wait states, set position 8 "OFF".
Interrupt Headers J5 and J6
The headers marked J5 and J6 allow the use of interrupts with the parallel ports. J5
selects IRQ2 through IRQ7 for Port 1 (U9 and J1), while J6 selects the IRQ for Port
2 (U16 and J3).
IRQ Header E2
Optional Cable Connector P4
Discrete access to both sides of all relays is provided by attaching the
optional cable (CA-108) to pin header P4 with the colored edge of the ribbon
cable attached to pin one. Removing all the jumpers connecting row P1 to P2
places the A-side of each relay at the on-board DB-37 and the B-side at the
optional cable’s DB-37.