Brian's Special Mission!

Okay, here's the deal. There's this bloke called Brian, right, and he's got this thing about putting perfectly normal Saturns into arcade cabinets, to give you that arcade-in-your-own-home experience, at a fraction of the cost of buying a real coin-op. Don't ask us why. Anyway, here's the sum total of Brian's technical knowledge, handily presented to you in convenient, easy-to-read html format, written by the man himself.

Wiring a Saturn Console into an Arcade Cabinet

Ever noticed that the best games on the Saturn are either ports of arcade games or direct conversions from ST-V (Titan) arcade games?

The only thing wrong is the fiddly little controllers and the fact that you can't play the damn thing when someone else wants to watch Coronation Street.

It makes much more sense to have the thing sat in a real arcade cabinet, so you can happily hammer away on the buttons during Athlete Kings, or wildy rotate the joystick and smash the buttons while beating up your mate in SFA 2.

What follows are instructions on how to get a Saturn up and running into an arcade cabinet, it's not that difficult and should work out a lot cheaper than buying a spare TV + 2 arcade style controllers for your Saturn.

What's Involved
It's a fairly simple procedure to get a Saturn into a cabinet, but it does require some soldering skills. The circuits that need to be made are very simple, and you won't invalidate your Saturn warranty (if you've still got one).

Some Background Information on Arcade Games
Without going into too much detail, there's basically two types of arcade cabinets. The first type being 'dedicated', these are usually expensive, have special controls and maybe some force feedback mechanism. Examples are things like Daytona, Virtua Cop, Manx TT etc

The second type are generic cabinets. These usually have 1 joystick and three or six buttons per player. They can have anything from Tetris to Mortal Kombat in them, the current game in the cabinet is usually on indicated by a card on the front glass and/or the lit 'marquee' at the top of the cabinet.

These generic cabinets are the ones we're after, specifically JAMMA cabinets. JAMMA (Japanese Amusement Machine Maunfacturers' Association - UK:R trivia dept) is a standard for arcade game PCBs, it defines a set of input and outputs that appear in a set position on the edge connector of the JAMMA board. So, in theory, any JAMMA board can be placed in any JAMMA cabinet; there are, however, a couple of exceptions...

Firstly the JAMMA standard only allows for 3 buttons per player, but games such as SF have six buttons. A 'six button cabinet' will have an extra connector which plugs directly into the board and is seperate from the JAMMA connector.

Secondly, JAMMA does not define the 'orientation' of the monitor. The monitor could be vertical (i.e. turned on it's side, as in 1943, Tetris etc.) or horizontal (like a normal TV, as in just about all games these days)

The type of cabinet we need is a 2 player, Six Button per player , JAMMA cabinet with a 19" Horizontal Monitor. (you can get a bigger monitor, but 19" is a nice standard/cheap size)

Some cabinets allow for the monitor to be rotated to play both horizontal and vertical games - this is even better. Just make sure you don't buy a cabinet which only allows the monitor to be vertical. You'll have to bend you neck 90 degrees whilst you're playing the games.

There is a general shorthand when refering to arcade cabinets something like Silverline 19" JAMMA 2 player 3 button V/H - Which means:- A Silverline (manufacturer) JAMMA cabinet with a 19 inch monitor, 2 joysticks with 3 buttons per joystick. The monitor can be either placed in either the Vertical or Horizontal position.

Some other terms which might help

Upright - standard size upright cabinet
Cocktail - Those old 'pub table' type games, where the monitor was inside the table and you sat down to play the game. These aren't really made anymore and don't have enough room inside them to poke around.
Mini/Midi/Slimline/Cabaret - All these mean a smalller version of a standard size cabinet. These usually have 3 or less buttons on them, as there isn't room for much else.

As regards dimensions, most (if not all) Upright JAMMA cabinets are designed to fit through a standard door. So as long as you don't get one with a 33" projection screen, you should be okay.

Parts Needed for the Project
You'll need to get hold of the following to do this, where possible suppliers are included at the end of the list.

1x Arcade Cabinet
Obvious really, I've included web pages of stuff for sale in the UK. You're probably better off looking in the phone book though, have a look at the section 'Getting The Arcade Cabinet' for more info.

1x Saturn
Again, obvious really 1x JAMMA finger board
These are also refered to as 'JAMMA Male Edge Connectors' and 'JAMMA Biscuits'. Basically it's just the edge connector (i.e. plug) off the end of a JAMMA arcade board, as long as you wire it in correctly you can get what ever is on the other end of it to play in an arcade cabinet.

1x small audio amp capable of being run off 12v DC
I recommend you get a cheap low watt mono amp kit from somewhere like Maplin. The reasons for this are:-
(i) They're fairly cheap (should be under a tenner)
(ii) They come with full instructions on how to make them as well as more general hints on soldering, identifying components etc.
Most of these amp kits run off anything between 5 to 20 volts, so they should all work off 12v DC. The reason it has to be 12v DC is that's what arcade cabinet supplies.

1x RGB Scart Cable
Just the standard RGB cable, you're gonna break this open - so I recommend you buy one specifically for this project and keep the one you (probably) got with the Saturn

2x Controllers
Again, you're breaking these open, so just get the ugliest/cheapest ones you can find. All you're really interested in is the chip inside it.

Now we get a bit more technical (Shit! - Jon & Gary).

You're going to have to make up a small circuit to get the video working; it's a very simple ciruit with only 4 components. These are:-

1x LM1881N
This is a very small 8 leg chip, it's used to seperate composite video synch (which arcade monitors need) out of composite video (which is where a scart TV generally gets its sync signal from). Knowing this, SEGA decided not to bother supplying a seperate composite synch signal out of the Saturn, even though one is listed in the pinouts of the AV port.

2x 0.1uf Capacitors
Pronounced '0.1 micro farads', but you can get away with '0.1 mew f'. These are small 'ceramic' capacitors, basically a flat circle of (usually) orange stuff with two wires sticking out of them. The capacitor will be marked 104Z. When getting these, make sure you DONT get electrolytic capacitors. These are small barrel like capacitors (usually blue) and will do us no good at all.

1x 680K ohm resistor
A small barrel shaped thing with 2 wires sticking out of it.

1x piece of Strip board
This is basically a board with holes in and copper tracks on the underside, used to make up circuits. Just get the smallest piece you can, you'll not be using most of it.

1x 8 pin 'dip' chip socket
This is just the socket for the LM1881N chip, you don't strictly need it as you could just solder the chip directly on to the strip board BUT a socket means:
(i) The chip will be easier to replace if it ever fails
(ii) You have no chance of damaging the small chip as your soldering iron will never come near it

You'll probably have to buy the capacitors, resistor and chip socket in packs. Just get the smallest number of components that you can, they only cost about 10p each.

The other stuff you'll need:

A soldering iron - a cheap one will do, no need for extra fine tips etc.

Some solder - obvious really

Lots of thin gauge multi-coloured insulated wire, you don't need different colours; it just makes life easier.

This is not neccessary, but a Digital Multimeter is immensely useful (You're telling me. The UK:Resistance Digital Multimeter is used almost daily - Gary). Just a cheap one from Argos will do.

Getting The Arcade Cabinet

There's a few of ways of getting arcade cabinets...
1) Wander around second hand shops. I've actually found arcade cabinets in a second hand clothes shop and a second hand washing machine shop. This is a fairly hit and miss method and not recommend.

2) Go into a local arcade, ask the manager if they've got any cabinets they want to sell. Not a bad way of doing it, just make sure you see the cabinet running. Also, plan to organise delivery yourself - an arcade is unlikely to want to drive a truck out to your house. Generally, if I buy cabinets from an arcade I don't bother getting the guy to plug them in, and assume they're not going to work when I get them home (saves you a lot of cash)- which is ok if you can fix them; a bit rubbish if you can't.

3) Find an Arcade Distributor phone up and ask for a cabinet. This is probably the easiest way of doing things (if they'll sell to you, some distributors refuse to sell games for home use), an arcade distributor does nothing but sell/lease/repair arcade games, and has a nice big truck to deliver them in. You'll pay slightly more than method 1 or 2, but it'll be less hassle. If the price seems a bit steep, ask them how much it would be without a coin-mech and just a 'credit button' instead. Multi-coin mechs cost a fair amount and can easily be moved from one machine to another; a button, on the other hand runs, to about 50p.

The good news is that the 'board' market is dying if not dead (i.e. the boards that go into the generic JAMMA cabinets we're trying to buy) So, you should be able to get hold of a cabinet cheaply - chances are if you don't buy it, it'll just end up in a skip.

This page has machines for sale in the UK:

But, as ever, you'll probably get more out of your phone book and a few hours ringing around distributors and/or arcades.

Wiring the Saturn into the Cabinet

Wiring in the Video
Normal arcade cabinets run of analogue RGB and composite negative synch. You can get hold of the RGB quite easily, but you need to strip the composite synch of out of the composite video signal.

Looking at the back of the SCART plug (i.e. this is really a TV's SCART socket)

You're interested in the following pins..
2.........Sound Right
6.........Sound Left (Mono)
7.........Video Blue
11........Video Green
15........Video Red
20........Composite Video
21........Frame Ground

If 21 (the actually metal) is not connected to ground one of the following pins can be used instead
4... Audio GROUND
17.. Video GROUND
18.. Blanking GROUND
13.. Red GROUND
5.. Blue GROUND
9.. Green GROUND

21 is connnected in all Saturn scart cables that I've seen, but you never know!

Simply take the Red, Green, Blue wires and solder them to the correct pins on the JAMMA biscuit. Solder Ground to Video Ground on the JAMMA biscuit, then solder another wire from that Video Ground on the JAMMA biscuit to another ground pin on the JAMMA biscuit.

Then you have to make up this circuit...

Click here for diagram

...and solder the generated Composite Sync to the Video Sync pin on the JAMMA biscuit. Take the +5V and ground from the JAMMA biscuit. If you plug in the console you should now have video in the arcade cabinet.

Wiring in the Sound
You could wire in stereo sound, but if you do you'll need two audio amps - and stereo isnŐt JAMMA standard. Put together your audio amp, wire in the left channel from the scart socket. Wire in ground and +12V to your audio amp (from the JAMMA biscuit), then wire in the output to the speaker pins on the JAMMA connector. You should now have sound.

Wiring in the Controllers
JAMMA only has an eight way joystick and 3 buttons. 6 button cabinets actually have a separate wiring harness for the extra buttons. For the joystick and first 3 buttons itŐs straightforward.

Trace the tracks on the controller board to find the ground (it'll be the track shared by all joystick directions/buttons) wire this into ground on the JAMMA biscuit. Once you've soldered in the common ground wire you need to wire in all the buttons/joystick directions.

The 'points' on the controller board you need to solder should look something like this:

The yellow parts are exposed metal which can be soldered onto, the green are sealed tracks on the board.

For each joystick direction/button solder onto the controller board a wire on the 'non ground' half of the junction point.

For the extra three buttons per controller, the easiest thing to do is to cut off the connector on the end of the extra wiring harness, figure out which button goes with each wire, and then just solder them onto the controller board.

JAMMA Pinout

The pinout for a JAMMA biscuit looks like this:

Click here for diagram

General Hints

If you've followed all of the above you should now have a Saturn in an arcade cabinet. The easiest way to do it is probably Controllers first, then sound and video.

If possible, just wire up the start button, joystick and a couple of buttons for one controller. Then plug this into your arcade cabinet, but don't turn the thing on. Then plug the Saturn into a TV as normal, turn the Saturn on and see if the arcade controller works; if it does wire in the rest of the player 1 controls, check it, then do the same for player 2. If it doesn't work then just check all the wiring for loose connections/shorts. Then wire in the sound, check that (you need to turn the arcade cabinet on this time), finally wire in the video.

The monitor will need to be adjusted for PAL Saturns, as they are generally set to 60Hz, rather than 50Hz. This is a simple adjustment pot on the monitor board.


Electronic Suppliers:-
You can get some stuff from Tandy (such as Soldering irons/solder wire etc.) but for actual electronic components you're better off trying:
or RadioSpares - can't find a web page for them, but here's some contact stuff for various UK suppliers (including RS) here and here

Also check your phone book for local hobbyist electronic shops, the components you need are fairly common; so most should carry them.

JAMMA finger board - fairly arcade specific, have a look here (look under 'Connectors'). You're after 2x28 Finger boards, or 2x28 Edge Connectors (2x28 just means 28 connections on each side of the finger board)

And try here (go to Video Arcade Game Supplies under 'JAMMA Finger boards')

As ever, check you phone book - look under 'Amusement Distributors/Suppliers/Caters' if you find one locally they may be able to help you out with some finger boards.

General arcade stuff

You can find a lot of useful stuff here

Talk about being a man with a mission! If any of you have the time or inclination to follow Brian's mighty guide, let us know - we'll come round to your house and offer medical and psychiatric support! Cheers Brian!