Pincoder Diagnostics Inc.  Version 2021.03.31.1434

ROM NAME
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06-switches (Williams sys7)



PURPOSE
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This test will show whether the CPU can sense all switches found in the following list:

    * Switches in the switch matrix (Numbered 01-64). See your game's documentation to
    identify which switches are included in this matrix.

    * DIP switches (Numbered 65-80: Top Bank Top switch, to Bottom Bank Bottom switch) on CPU
    board.

    * Coin door switches: ADVANCE (Number 81), AUTO_UPDN (Number 82)

    NOTE: The HIGH SCORE RESET switch on the coin door is included in the switch matrix.

All other switches in the game - including the special solenoid switches are not wired to a
PIA on the driver board and therefore cannot be sensed by software.



PROCEDURE
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Before running this test ensure the following:

    * The ball has been removed from the outhole, and

    * The dip switches all are all off, and

    * The COMMAND ENTER switch is not being pressed

    * The AUTO_UP_DOWN switch is down.

When you then power on this test the following values will be shown on the displays:

    * MATCH: The total number of closed switches found.

    * P1-P4: The switch numbers of the first 12 closed switches found.

If there are more than 12 closed switches found you will need to open some of the ones shown
in order to reveal the other closures.



EXPECTED RESULTS
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If you have started out this test as outlined above then all switches should be open and
therefore the MATCH display should read "00". No other numbers will be shown.

Closing switches by hand should reveal their switch number on the P1-P4 displays, and the
MATCH number should indicate the total number of closed switches sensed.




ABOUT THE DIP SWITCHES (and PIA1)
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In order for the DIP switch settings to be picked up by the CPU, the COMMAND ENTER pushbutton
switch must be pressed and held down. This is by design in the circuitry.

Test all DIP switches. If there are "dead" or "stuck" switches, Trace signals on SW2, PIA1,
IC2, and IC6 to determine where the fault is.

Essentially, PIA1 sets CA2 LOW while sending rotating signals out on pins PA0-PA3 and looks
for incoming signals on PA4-PA7. IC2 and IC6 deal with things in between. IC6 is also used for
the DISPLAYS, so if you are also having trouble with DISPLAYS then it is likely IC6 that is
causing the problem.



ABOUT THE MATRIX SWITCHES (and PIA2)
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Check any switches shown for unintended shorts. If you are seeing multiple switches shown, and
they are numbered (01-64), cross reference them to the switch matrix for your game and see if
they form a single column or row in the matrix. If so this could indicate a stuck/bad pin on
PIA2, IC15, IC16, IC17, or IC18.

Use a logic probe with this test to ensure that signals on PIA2 are working. Trace the
signal along the SWITCH MATRIX DRIVES from PIA2 PBx pins, through IC17 and IC18, and onto to
2J2. These 8 signals will continually round-robin pulse.

If the outputs are working and a switch is closed a signal will be seen on the SWITCH MATRIX
INPUTS. Follow the signal along from 2J3, through to IC15 and IC16 and onto PIA2 PAx

The SWITCH MATRIX DRIVES are associated in the switch matrix in terms of columns, and the
SWITCH MATRIX inputs are associated as rows. Therefore, if you have an entirely dead or always
closed column, the problem is in the SWITCH MATRIX DRIVES. If you have a problem with an
entire row, the problem is with the SWITCH MATRIX INPUTS.

Pincoder Diagnostics Inc. Version 2021.03.31.1434
