Deducing Switch settings FAQ
(2nd March '95 John Keay)
How can I find out the switch settings for game X?
1) Look in the cabinet.
Many games have lists of switch settings in the cabinet, or
on scruffy bits of coffee stained paper thrown in the bottom of
2) Look on wiretap.spies.com
The directory /pub/game_archive/switchSettings has lots of
useful switch settings.
3) Figure them out from scratch.
This is the fun part. How can you do this without it taking
forever (and without destroying you power supply and game
board in the process).
Firstly switch settings are often only resampled at reset
(or sometimes on leaving test mode) so usually you will
have to power the game on and off to try various combinations.
a) Test mode
This is the easy one. Often boards have built in test modes
that will allow you to play with the switches and will
automatically translate the switch settings into "English"
and display the info on the screen.
Of course you will need to know which switch (or pin) puts
the board into test mode. This is sort of a circular problem
but see below.
b) Reset button
Powering a board on and off again and again will not do the
board and the power supply any good, so if the board has
a reset button, use it.
c) Test mode (revisited)
Sometimes the board may resample the switch settings as it
leaves test mode. In cases where the test mode doesn't give
you any clues this feature can be used to avoid having to
power the board on and off. AS I SAID YOU SHOULD DO ANYTHING
TO AVOID POWERING UP AND DOWN LOTS OF TIMES, AS THIS MAY
DAMAGE YOUR BOARD/MONITOR/POWER SUPPLY.
d) Look for a test mode switch
Make a note of the current switch settings (because they
my be good defaults), power the board up and change
the position of ALL the switches. If nothing changes
reset board. If a test mode switch exists you will
now probably be in test mode. If a switch exists
to flip the screen over you may well find it at this
e) Pause switch
If you flip the switches over and the board doesn't
power up correctly you may have changed the pause
switch. You will have to use the techniques below
to locate this switch before you can proceed.
As an aside, have you ever received a new board
with the pause switch set? If you ever get a board
that doesn't work always try flipping the switches
and powering up again. The pause switch may be on
and/or the board's test mode might help debug.
f) Try different combinations of switches.
Lets say you have 16 switches, well that is _ONLY_ 65536
different combinations! Fortunately most function are
controlled by a single switch and if you do things
right it should only take 4 tests to find any single
switch function (for our 16 switch example).
The key here is 'binary search'. The process might
be obvious to folk out there (esp. anyone who has
spent too long in front of a computer), but here it
is in writing. Lets say our initial 'flip all the
switches over' test confirmed the existence of a
test mode and we want to find out which switch
Split the switches into 2 equal groups 'A' and 'B'
and change the state of all the switches in group 'A'.
Reset the board. If this effected the board entering
test mode then the test mode switch is in group 'A'
(so we can ignore group 'B') if not then we can
concentrate on group 'B' (and ignore group 'A').
Either way we now only have half as many switches
to worry about. We simply repeat this process until
we know which switch controls test mode.
g) Switch priority
Certain switches over ride others (for example a
pause switch will usually over ride test mode).
So you may have to locate higher priority switches
before you can find the lower priority ones. i.e It's
no good looking for a cocktail/upright switch until
you can avoid pause and/or test mode switches.
h) Common switches
Dip switches are used to control all sorts of functions
here are a few of the more common ones.
Pause - Usually highest priority - stops the game
Test mode - Usually 2nd highest priority
Cocktail/Upright - In Cocktail mode player 2 will be upside down
Screen Invert - You often don't need to reset the board
to find this. Not to be confused with
Starting lives - Press player 1 start and count the lives
Bonus lives - This info is often written on attract mode
screens (often multiple switches)
Language - The attract mode screens often show this.
(usually multiple switches)
Difficulty - Usually the hardest settings to guess. If
anyone has any fast methods of finding these
I'd be interested. (usually multiple switches)
Credits/Coin - Sometimes all these switch on gives
free play (usually multiple switches)
Free Play - Sometimes free play has it's own switch
Demo mode sound - Do you get sound in attract mode?
Continue enabled - Does the game let you continue after
you have died. Sometimes multiple switches
control how many times you can continue
Cheat mode - In some games this switch stops you
from loosing lives and can be used
for play testing.
4) Ask the net
If all else fails you can drop a line to the net in the hope
that some lazy so and so, has the switch settings but hasn't
sent them to the archive yet. ;-)
* John Keay ! Texas Instruments Ltd. *
* work: email@example.com ! Bedford, U.K. *
* home: firstname.lastname@example.org ! *
* Disclaimer: All opinions expressed herein are personal. etc etc *