JAMMA-Prog - Game Controller JAMMA Interface
A JAMMA compatible arcade machine will have the power supply, monitor,
speaker, joysticks and buttons all hooked up to a single cable harness known
as a JAMMA harness. When the control panel features more than three fire
buttons per player, there is usually a second, small harness known as a kick
harness which carries the wires to these extra fire buttons. The purpose of
this board is to be an adapter between the JAMMA/kick harness and third
party controller boards such as the Brook Fighting Board series as well as
hacked game pads. The RGB and audio amplifier are located another board, the
SCART2ARC30, sold separately.
The joystick and button section is divided into two sides: the JAMMA side,
which plugs into the JAMMA harness and the kick harness if there is one, and
the controller side, which is connected to a controller board for each
player. They are connect either via the terminal array or the 20 pin
fighting board connectors. The JAMMA side and controller sides each have
their signals routed to a strip of pins (dark red and dark blue on the
diagram). To program the controls, a jumper wire is connected between the a
JAMMA pin and a controller pin on the strip, this is repeated for every
joystick and button signal.
In addition to being a connection adapter and programmable pin matrix, the
JAMMA-Prog provides some active circuits which are handy in certain
applications. The first is the start-up hold circuit. The purpose which is
to activate (connect to ground) an input for a short time at power up. Many
third party controller boards such as the Brook Fighting Board series and
the Akishop PS360+ require holding down a particular button on start-up to
put the controller board into the desired operation mode. This can be
programmed via jumper wires to done automatically, so the user does not need
to remember to hold a particular fire button down when turning the console
on. There are two start-up hold circuits provided (one for each player).
The second is the trigger inverter circuit. This is useful for game pad
hacks which feature analog triggers. An analog trigger usually has a
potentiometer connected which provides 0V in the neutral state and VCC when
fully depressed. This is the opposite of a standard button which is normally
pulled up to VCC and connected to ground (0V) when pushed. The trigger
inverter circuit inverts the signal from the JAMMA button so it is
compatible with the analog trigger input. There are four trigger inverter
circuits provided, two for each player.
Resources
Change Log
16/6/2020 - Page created.
