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COMM-180-M/S Headers COMM-180-M/S Jumpers
J1, Mini Phono Jack, 3 Pin JP1, Microphone/Headset
J2, Modular Phone Jack, 4 Pin JP2, MOSART Interupt Select
J3, RCA Audio Connector JP3, Audio Output Mute (?)
J4, I/O Expansion Header JP4, SCSI Termination Power
J5, SCSI Bus Header JP5, 5380 -DACK Signal
J6, Power Header *

J1, Mini Phono Jack
  PIN             DESCRIPTION
  ---             -----------
  tip             Microphone/Audio In
  middle ring     Earphone/Audio Out, or Microphone Bias (see JP1)
  base ring       GND
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J2, Modular Phone Jack
            DESCRIPTION     PIN #
           ------------     -----
                     nc     1
                    tip     2
                   ring     3
                     nc     4

             nc = no connection (pin is floating)
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J3, RCA Audio Connector, Audio Out
  PIN             DESCRIPTION
  ---             -----------
  tip             Audio Out
  shield          GND
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J4, I/O Expansion Header
           ------------     -----     ------------
              +5VDC PWR     1   2     +5VDC PWR
                    GND     3   4     GND
                    -RD     5   6     PHI
                    -WR     7   8     -RESET
                      E     9  10     -LIR
                   -NMI     11 12     -EXP SEL (E0-FF)
                  -WAIT     13 14     nc
                  -INT0     15 16     -HALT
                     ST     17 18     nc
                     A0     19 20     A1
                 -TEND0     21 22     A2
                     A3     23 24     A4
                 -DREQ0     25 26     -I/O ENABLE
                   8MHZ     27 28     RESET
                     D7     29 30     D6
                     D5     31 32     D3
                     D4     33 34     D2
                     D1     35 36     D0
                    GND     37 38     GND
                     nc     39 40     nc

             nc = no connection (pin is floating)
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J5, SCSI Bus Header
           ------------     -----     ------------
                    GND     1   2     B0
                    GND     3   4     B1
                    GND     5   6     B2
                    GND     7   8     B3
                    GND     9  10     B4
                    GND     11 12     B5
                    GND     13 14     B6
                    GND     15 16     B7
                    GND     17 18     PARITY
                    GND     19 20     nc
                    GND     21 22     nc
                    GND     23 24     nc
                    GND     27 28     nc
                    GND     29 30     nc
                    GND     31 32     -ATN
                    GND     33 34     nc
                    GND     35 36     -BUSY
                    GND     37 38     -ACK
                    GND     39 40     -RESET
                    GND     41 42     -MSG
                    GND     43 44     -SEL
                    GND     45 46     CTL/-DATA
                    GND     47 48     -REQ
                    GND     49 50     IN/-OUT
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J6, Power Connector
The power connector is usually the same connector found on 3.5" floppy disk drives, making it convenient to use standard PC power supplies with this board.
            DESCRIPTION     PIN #
           ------------     -----
                 +12VDC     1
                    GND     2
                    GND     3
                  +5VDC     4
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JP1, Microphone/Headset
This jumper configures the mini phono jack J1. The default setting provides bias (power) to an attached microphone through the middle ring of the connector. It can also be configured to connect the audio output of the MOSART to the middle ring of the connector for use with an earphone/headset.
JP1 Image

          Yellow: +5VDC bias (power) to J1 middle ring (default)

             Red: +5VDC bias (power) to J1 tip, audio out to middle ring

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JP2, MOSART Interupt Select
This jumper connects one of the MOSART output lines TxEMPTY, TxRDY, RxRDY, or SynDet to J4 pin 15 (-INT) (through U1).
JP2 Image

               1: TxEMPTY
               2: TxRDY
               3: RxRDY
               4: SynDet

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JP3, Audio Output Mute (?)
This jumper provides a connection between the center pin of RCA connector J3 abd GND. I am not sure what this might be for. It is not mentioned in my hardware manual. The only use I can see for it might be to provide a connection for muting the audio output.
JP3 Image

             Red: J3 center pin to GND

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JP4, SCSI Termination Power
This jumper connects +5VDC to either the on-board SCSI termination resistor packs (the default), or to the SCSI bus connector J5 pins 25 and 26.
JP4 Image

          Yellow: +5VDC to on-board SCSI bus termination (default)

             Red: +5VDC to SCSI bus J5 pins 25 and 26

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JP5, 5380 -DACK Signal
This jumper determines the source for the NCR 5380 SCSI chip's -DACK signal. It connects either data bit D0 of I/O port F4, or the I/O port F4 select signal (the default) to the 5380's pin 26.
NOTE: This jumper's default setting is "hard wired", there is a circuit board trace installed between the two specified pads. To change the setting you will need to cut this trace and install a jumper as needed. This jumper is located on the backside of the circuit board "under" the NCR5380 SCSI Controller chip.
JP5 Image

          Yellow: I/O port F4 select to 5380 -DACK (default)

             Red: I/O port F0 data bit D0 to 5380 -DACK

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