The following was taken directly from an archived copy of, no alteration has been done to the text below and I am not responsible for any inaccuracies or errors.

JAMMA Origins Paper

From: (Noel Tominack, ACS, X3861)
Subject: My Data Communications Paper
Date: 4 AUG 94 12:05:03 GMT

	Well, some people wanted to see it, so I thought I would post
it here.  My paper talked about the evolution and implementation of the
JAMMA standard.  Most of the material is from this newsgroup, hope you all
like it.
	I was told the other part of the paper was riddled with inaccuracies
but I hope this one is better.  If you all see something that isn't right,
please let me know

* Noel J. Tominack (  |
* University of Maryland Baltimore County |
* All opinions are mine mine mine! 	  |
* ________________________________________|

p.s.  I got a B in that class

-------------------------BEGIN INCLUDED TEXT------------------------------

The Video Game Industry Learns from
the Data Communications Industry

by Noel Tominack


	When an innovative technology is successful in one
particular field or application, it is the nature of other
industries to try and copy this success by trying to apply
the technology to meet their own needs.  This cross-
pollination of ideas brings technologies together that nobody
thought were related, much less possible.
	This paper will focus on what the video game industry
has picked up from the data communications industry.  Its not
too surprising, since both have recently rapidly advanced
because of advances in computers.  The first part with deal
with how an ailing branch of video games was revived by
taking a lead from the RS-232 standard; and the second part
will cover how Local area network principles were applied to
handheld video games to add a whole new aspect to their


	When the RS-232 standard was first introduced, it was
little more than an agreement on what each connector RpinS
would do.  But over time it had  become the de facto standard
for serial devices.  Modems, printers, and serial cards all
adhered to the RS-232 standard.  Because of this
standardization, its possible to hook up a printer or modem
manufactured 15 years ago to your band-new PC and it will
work.  So what does that mean to the video game industry?
For the manufacturers of arcade machines, it means a lot.
	Now, for the sake of this paper, the arcade machine will
be broken down into two basic parts.  The first is the
RboardS (also referred to as the logic board, or printed
circuit board--PCB for short) which houses the ROM chips of
the game itself and related microchips.  The second is the
RcabinetS which is the wood cabinet which houses the monitor,
the power supply, the control panel, the sound system, and
the coin mechanism.  The two together make an entire arcade
machine, and this section deals with how the board and
cabinet communicate with each other.
	In the early 1980s, the video arcade business was
booming and arcade were springing up all over the
countryside.  Demand for machines was high and all the
manufacturers were concerned about was selling new video
arcade machines, not compatibility.
	According to Steve Ozdemir, president of the Video
Arcade Preservation Society "you can go to the KLOV1 and find
any manufacturer who produced games in 1982 and also in 1986,
and I can assure you that those two games are NOT compatible
in any way!"   Mr. Ozdemir goes on to add "In fact, if you
pick randomly any two games from one manufacturer, you'll
probably have two incompatible games that will never be
backward or forward compatible--the hardware changes too
quickly!"(1)  In the rush to put new products out on the
market, arcade machine manufacturers decided not to worry
about compatibility between different boards and cabinets.
The arcade boom was quite strong and the demand was still
great for whole machines.  There is also another reason
arcade manufacturers kept making incompatible machines "This
also has a lot to do with the secretiveness of the time--many
boards werenUt even marked, companies were afraid of the
competition reverse engineering" says Chris McBride, another
Video Arcade Preservation Society member(2)
	One of the most interesting cases of incompatibility has
to do with 2 Atari games, Asteroids and Asteroids Deluxe.
They use identical wiring harnesses and cabinets.  However,
when one board is put into the other's cabinet, play is
nearly impossible.  "The left and right rotation buttons are
reversed, pressing start will add credits to the machine, and
putting coins in will start your game."(3).  Obviously there
was a need for some standardization, at least within the
individual companies.
	Now there was some compatibility at the time within a
single manufacturers' line.  At Williams Electronics,
swapping the ROM chips and control panel was enough to
convert Stargate/Robotron/Joust into one another.  Both
Bally-Midway and Nintendo used the same harness on their Pac-
Man and Donkey Kong series games respectively(4).  That way
the arcade operator only needed one cabinet and could
purchase conversion "kits" for far less than a full game.  It
was a win-win situation; manufacturers could save on building
and shipping costs since they didn't need to make as many
cabinets, and operators could save the shipping costs of a
300-pound machine, as well as space in their arcades(2).  But
it would take outside events to accelerate this trend, and
that is exactly what happened in 1983.
	Just as quickly as the boom in the arcade business came,
it went.  The arcades that sprang up closed and the ones that
managed to remain open had far less income to spend on whole
games.  During this time there were still no industry-wide
standards for boards and cabinets, so arcade operators would
"hack" old cabinets to get new boards to work in them.
Several manufacturers also went out of business or merged
with other companies, reducing the number of number of
	By late 1984, there was a small boomlet in the arcade
industry, as the personal computer market expanded, it drove
down the price of memory and microprocessors.  Now video
games could have better graphics than ever.  But still the
problem remained, how to expand the industry with little
expense on all sides as possible.  That is when someone came
up with the idea to standardize the connections between the
boards and the cabinets.  This is what brought on the JAMMA
	The JAMMA (short for Japanese Amusement Machine
Manufacturers Association) wiring standard uses a set of pre-
defined pinouts for power inputs, control inputs, and
audio/video outputs.  The idea being that once a cabinet is
wired with a JAMMA connector, all you have to do is plug in a
new board to convert a game.  Its not always that easy with
some of the more complex games or the ones that have special
controls, but the idea is sound (5).
	The idea is sound because it was proven with RS-232
decades before JAMMA.  If all the manufacturers adhere to the
same standard, it makes it easier for manufacturers to make
compatible products.  Any JAMMA board can be put into any
JAMMA cabinet (at least for testing purposes).  Since the
wiring harness was standardized, third parties could
manufacturer wiring and cabinets, thus lowing the cost of
producing a game.  Also, an arcade operator could now easily
convert a game and bring the new one into service quickly, a
big plus in a busy arcade where game turnover is high.
Unlike the complete incompatibility problems of the early
1980s, any arcade board manufactured from 1987 on will work
in any JAMMA cabinet.
	The JAMMA standard used a 56-pin edge connector on the
board (see Appendix 1) with inputs and outputs common to most
video games.  These include power inputs (5 volts for the
game and 12 volts for sound); inputs for 2 joysticks and 2
buttons for each; analog RBG video output with negative
composite sync; single-speaker sound output; and inputs for
coin, service, test, and tilt (the former to accept game
credits and the latter to maintain the board).
	While JAMMA is a standard, it does have some limitations
"The different game manufacturers couldn't decide which way
to turn a monitor for vertical [screen orientation] games.
Consequently, some games come out upside down" says arcade
machine guru Richard Schieve (5).  Also, since the wiring is
only for one speaker, games with stereo sound need another
	Recent trends in arcade machines are having more than
two buttons (particularly for the genre of fighting" games) and the use
of 4-player games.  While these games maintain the original
JAMMA harness, they employ secondary harnesses to handle the
extra inputs(6).  Another way arcade manufacturers buck the
JAMMA standard is a 'back to the future' solution--ROM chip
replacements for conversions within a manufacturers. All of
Konami's 4-player games and the sequels to popular "fighting"
games can be converted with ROM upgrades.
	Unusual applications of the JAMMA standard are SNK's Neo
Geo System, the "Super Gun", and the adapting of older games.
While the Neo Geo System uses a JAMMA harness--the system
uses replaceable ROM cartridges to change games, and the
system may house from 1 to 4 separate games2.  The "Super
Gun" is a consumer electronic device that allows a person to
play JAMMA-compatible games at home using their TV and a wide
variety of controllers.  Finally, hobbyists and arcade
operators are breathing new life into old games by adapting
them to fit into JAMMA harnesses(5).
	The JAMMA standard allowed an industry on the verge of
collapse to bounce back and made life simpler for anyone
involved with arcade games.  With the advances in game
technology, there is talk of creating a JAMMA II standard to
overcome the limitations that JAMMA now has.  While this is a
good example of how the video game industry has learned from
the data communications industry, lets look at a more direct
technology transfer.

[part about handheld videogames using LAN technology deleted becase the
Game Boy segment has inaccuracies and besides, theis is a newsgroup for
arcade machines anyway]


	The video game industry was founded on the advances of
microprocessors and computer technology; and as this
technology grew to include data communications; that too
worked its way into the video game industry with very visible
and successful results.
	Up until 1985, arcade machines were often complete
incompatible with other games, even from the same
manufacturer.  This created a lot of problems compounded by a
sudden bust in the arcade industry in the mid-1980s.
Economic need and end-user demands required a set of
standards to make life easier for the arcade operators.
Because of the JAMMA standard, all arcade games use the same
wiring harnesses and can work in any JAMMA cabinet, reducing
costs for manufacturers and operators, not to mention
simplifying the whole process of game conversions.  But as
the arcade machines require more and more inputs and outputs,
the JAMMA standard may be superseded by a new industry-wide
standard for future machines.


1.  Ozdemir, Steven--Video Arcade Preservation Society
President, Email

2.  McBride, Chris--Video Arcade Preservation Society
President, Email 26 feb 94

3.  Jefferys, Doug RAdapter to Plus Asteriods Deluxe Board
into Asteriods Harness (and vice versa)S, Copyright 1993--
available via gopher from

4.  McBride, Chris--Video Arcade Preservation Society
President, Email 28 feb 94

5.  Schieve, Richard RJAMMA Cabinet Revisited and What IUm Up
toS Usenet 19 Jan 94

6.  Deitch, Johnathan RControl Panel Wiring 101S Usenet 28
Apr 1994


1 The KLOV refers to the "Killer List of Videogames" which lists and describes
every arcade machine manufactured to date

2 SNK also makes a home version of the Neo Geo system which utilizes a stadard
television and uses the same cartridges as it's arcade counterpart