Reference Manual

PMAC-Mini PCI Hardware Reference Manual

Connector Pinouts 33

J3 JTHW (26-Pin Header)

Front View

Pin # Symbol Function Description Notes

1 GND Common PMAC Common

2 GND Common PMAC Common

3 DAT0 Input Data-0 Input Data Input from Thumbwheel Switches

4 SEL0 Output Select-0 Output Scanner Output for reading TW Switches

5 DAT1 Input Data-1 Input Data Input from Thumbwheel Switches

6 SEL1 Output Select-1 Output Scanner Output for reading TW Switches

7 DAT2 Input Data-2 Input Data Input from Thumbwheel Switches

8 SEL2 Output Select-2 Output Scanner Output for reading TW Switches

9 DAT3 Input Data-3 Input Data Input from Thumbwheel Switches

10 SEL3 Output Select-3 Output Scanner Output for reading TW Switches

11 DAT4 Input Data-4 Input Data Input from Thumbwheel Switches

12 SEL4 Output Select-4 Output Scanner Output for reading TW Switches

13 DAT5 Input Data-5 Input Data Input from Thumbwheel Switches

14 SEL5 Output Select-5 Output Scanner Output for reading TW Switches

15 DAT6 Input Data-6 Input Data Input from Thumbwheel Switches

16 SEL6 Output Select-6 Output Scanner Output for reading TW Switches

17 DAT7 Input Data-7 Input Data Input from Thumbwheel Switches

18 SEL7 Output Select-7 Output Scanner Output for reading TW Switches

19 N.C. N.C. No Connection

20 GND Common PMAC Common

21 BFLD/ N.C. No Connection

22 GND Common PMAC Common

23 IPLD/ N.C. No Connection

24 GND Common PMAC Common

25 +5V Output +5VDC Supply Power Supply Out

26 INIT/ Input PMAC Reset Low is Reset

The JTHW multiplexer port provides eight inputs and eight outputs at TTL levels. While these I/O can be used

in un-multiplexed form for 16 discrete I/O points, most will utilize PMAC software and accessories to use this

port in multiplexed form to multiply the number of I/O that can be accessed on this port. In multiplexed form,

some of the SELn outputs are used to select which of the multiplexed I/O are to be accessed.