Beginners Guide To Candy Cabs
An arcadeotaku.com FAQ by SuperPang
- 1 What is a Candy Cab?
- 2 How much do they cost and where can I buy one?
- 3 Are they easy to transport?
- 4 What is JAMMA?
- 5 What is JVS?
- 6 So, how do I run JVS games in my JAMMA cabinet or vice versa?
- 7 What’s a PCB?
- 8 What about monitor resolutions?
- 9 What’s a “tri-sync” monitor?
- 10 How easy is it to rotate a monitor?
- 11 What about picture adjustment?
- 12 What is degaussing?
- 13 What is screen burn?
- 14 Do I need a Step Down?
- 15 Are control panels/buttons/joysticks interchangeable?
- 16 What’s a kick harness?
- 17 What about MVS/Atomiswave etc?
- 18 What are these controls inside the machine?
- 19 What about credits?
- 20 So how would I go about swapping games then?
What is a Candy Cab?
“Candy Cab” is the western term commonly used for Japanese sit-down style arcade cabinets. It was derived from the name of some of SNK’s first and most common machines, which were also some of the first models to be imported, the Neo “Candy” range.
How much do they cost and where can I buy one?
At the time of writing, most machines tend to sell for 400-800 GBP depending on model. In the US, 300-1,200 USD.
There are few “retailers” of candy cabs outside Japan. None in the UK, a couple in France, a couple in the US, one in Australia... Most are purchased in group buys arranged on forums. The best way to buy is privately from another gamer. Keep an eye on our sales forum!
Are they easy to transport?
A lot easier than “woodies” that’s for sure! Most weigh 80-120kg and are roughly 75cm wide by 90cm deep by 145cm high. They have two or four casters/wheels and are usually moved by tipping the machine back (some even have handles!) Most can be taken apart in sections; people have been known to fit them in cars this way! If doorways are your issue, most control panel assemblies can be detached.
What is JAMMA?
A wiring standard for arcade machines introduced in 1985 by the “Japanese Amusement Machine Manufacturers Association”. In this context, “JAMMA” refers to the wiring standard on the 56 pin JAMMA connector which consists of various inputs and outputs such as video, controls, credits etc. Most generic arcade cabinets produced throughout the ‘90’s are “JAMMA”.
Put simply, JAMMA is the interface you plug your game PCB into. One universal interface meant that arcade operators could add new games to existing machines when the old titles weren’t selling any more.
JAMMA+ refers too a slight variation on the JAMMA standard, such as an auxiliary harness for extra buttons.
What is JVS?
“JAMMA Video Standard”. JVS is essentially JAMMA 2. An updated standard created in the mid-to-late 90’s to improve upon JAMMA’s shortcomings. JVS uses separate connections. A HD-15 type video connection (commonly known as a VGA connector although this refers to a resolution really), RCA audio connections (stereo!), JST power connections (now with 3.3V!) and, perhaps most importantly, more advanced controls are handled via an I/O PCB within the cabinet which connects to the game hardware by USB cable.
So, how do I run JVS games in my JAMMA cabinet or vice versa?
Simple answer, with an I/O (input/output) board.
Running JVS in a JAMMA cab: There are two main types of JVS-JAMMA I/O used with Japanese machines, SEGA and Capcom. The SEGA I/O does not have a sound amplifier so you will need one separately if your machine doesn’t have a stereo amp. The Capcom I/O has a built in amp that converts to mono. It also has a CPS2/3 kick connector for ease of button wiring. So for ease of use, the Capcom I/O is pretty much plug and play whereas the SEGA one might save you a few quid if you have the right machine or extras.
The only other issue you should be aware of is power. A Naomi cartridge system will work on a JAMMA machine with an I/O but a Naomi GD ROM will probably not as it requires a JVS power supply. You will need to fit one separately, or alternatively some machines such as the Blast City and AWSD are JAMMA/JVS hybrids and come equipped with the necessary power connections. It is sometimes possible to power a Naomi 2 GD ROM system by turning the 5V line up fully but this is not advised as it could kill your I/O, or worse!
Running JAMMA in a JVS cab: Slightly simpler, a JAMMA-JVS I/O connects to your cabs JVS connections and you plug a JAMMA PCB into it. The ones to look out for are the Konami and Namco branded models for Windy II and Cyber-Lead, they will work with any JVS machine. River Service also make one. Remember though, if you don’t have a monitor that supports 15KHz, you’ll need some sort of upscanner/upscaler.
What’s a PCB?
“Printed Circuit Board”. The game itself, whether a dedicated hardware/software board or a motherboard with detachable software cartridges (such as Neo Geo MVS, Taito F3 etc).
What about monitor resolutions?
There are three you need to know about:
15.72KHz Standard Resolution (CGA) Most JAMMA games are standard resolution. All JAMMA machines support “15k” out of the factory. Pretty much equivalent to a 240p image via a decent RGB Scart lead on a decent CRT TV.
25KHz Medium Resolution (EGA) You only need to worry about this if you want to play games usually found in dedicated machines, such as SEGA “model” systems. Most Japanese 15k monitors are dual-sync and support 24k as well, such as the Nanao MS9 found in Egret II and New Astro City.
31.55KHz High Resolution (VGA) Pretty much equivalent to an old 640x480 CRT PC monitor. Usually supported on JVS systems (which already have the VGA type connector of course). Most hardware with 31k output also supports 15k via a dipswitch. SEGA Naomi being the most popular example. There are various 31KHz only monitors (such as in the Naomi Universal machines) and then there are tri-sync’s…
What’s a “tri-sync” monitor?
One that supports 15, 25 and 31KHz input either by auto-switching or dip-switch, meaning one machine can support all modern arcade systems. Tri-sync’s are very sought after for this convenience but suffer a slight loss in 15Khz picture quality because of the higher native resolution. This varies between manufacturers but tri-sync’s usually have more pronounced scan-lines and less colour depth than a dual-sync. Only really an issue for the very anal!
Some dual-sync monitors can be upgraded to tri-sync by replacing the chassis. Wei-ya make a tri-sync chassis that is often compatible with the tubes in candy cabs. Yoke readings must be checked first and results can vary.
How easy is it to rotate a monitor?
Most candy cab monitors are rotatable. Usually this requires removing or lifting up the front section, disconnecting or loosening any short cables to the monitor, unbolting the monitor, lifting it out slightly and rotating 90 degrees anticlockwise, and finally rotating the bezel/surround. With 29” monitors this is usually a two man job and you should be extra cautious if your monitor does not have a protective frame around the neck-board and chassis at the back.
A few machines however, have a rotation mechanism to make things easier, the most common being the Taito Egret 2 which has its monitor mounted on a wooden disc meaning one pair of hands can rotate it with minimum effort in a couple of minutes.
What about picture adjustment?
Most machines have a remote board inside the control panel containing pots to adjust settings such as vertical and horizontal size and position, brightness and R,G,B colour gain. (Taito remote boards tend to hide behind the coin mechanism.) There are also pots for more complex adjustments on the monitor chassis (the PCB attached behind the tube). On some older models of monitor, all pots are on the chassis, on the most modern, picture settings can be adjusted via an on screen display.
What is degaussing?
CRT monitors are prone to magnetization from the earth’s magnetic field when moved. This manifests in purple or green patches at the corners of the picture. Most monitors have a degaussing coil around the monitor and one push of the degauss/de-mag button eliminates the issue. Some monitors automatically degauss at power-up, like a TV. If your monitor has no degaussing coil, you can use a special wand to get rid of the magnetization.
What is screen burn?
“Screen burn” or “burn in” occurs when a bright static image is displayed on a CRT for a prolonged time, leading to weakened phosphor in certain pixels and a ghost image permanently on the screen. Screen burn is common on arcade monitors that have had a lot of use with games with inadequate attract/demo sequences or permanent text such as “Insert Coin” logos. Severe screen burn can result in a faint image of a static screen or text that is visible even when the monitor is off. Unfortunately, it cannot be reversed. When buying a cab, “Is there any screen burn” should be your first question.
Do I need a Step Down?
Japanese mains voltage is 100V so unless your power supply has been replaced or your machine has had an internal transformer fitted, you will need an external “step down” transformer to run the machine on 230V European mains voltage.
Most cabinets are rated at 100-150W but will consume more power with more demanding hardware. A 300W (VA) rated step down is recommended to avoid over-heating.
If you’re in the US, you can run the machine directly off the mains. Even though the US standard is 120V, mains voltage fluctuates more than you might think and power supplies are built with tolerances to withstand this. If you want to be extra cautious you can always use a transformer.
Pretty much all SEGA machines from the Astro City onwards use the same size control panel plate and are interchangeable (Eg Blast, Net, VS City). Konami Windy panels are also the same size. Taito Egret 2, 3 and Atomiswave SD panels are interchangeable as well. A SEGA panel will fit one of these Taito machines, albeit with gaps, whereas a Taito panel won’t fit a SEGA machine.
The two biggest manufacturers of arcade controls in Japan are Sanwa Denshi and Seimitsu. Most of their joystick models will fit most of the above control panels provided you have the correct mounting plate. Newer machines are wired with a 5 pin connector for joysticks, older models have individual connectors for each microswitch. Bear this in mind when purchasing new joysticks.
The Japanese have a very simple approach to buttons. The standard size is 30mm with 24mm for start/select buttons and they are available in snap in or screw in varieties. Each button has two pins, either can be used as a ground as the plunger is simply completing a circuit to register a button press.
What’s a kick harness?
The JAMMA standard uses only three buttons per player. Naturally this caused a few problems when Street Fighter came along, so Capcom included an auxiliary harness for the “kick” buttons which became known as the “kick harness”. A kick harness is simply a wiring harness that connects extra buttons to the game PCB, either directly or via your cabinets wiring or control board. Capcom CPS1 games have their own kick harness whilst CPS2 and 3 use the same type. Other games that use an auxiliary button harness include Namco fighters such as Tekken and Midway fighters such as Mortal Kombat.
What about MVS/Atomiswave etc?
When SNK created their Multi Video System, they added a few extras, including a fourth button using one of the two spare pins on the JAMMA harness and a select button on the other. SNK also released a JAMMA spec 1-slot motherboard with JAMMA spec machines to match. Naturally, button 4 remained. Most other manufacturers started wiring button four into their JAMMA machines and certain other developers such as IGS started utilizing this extra button as well.
Sammy went a step further by using the same pin SNK used for select for Atomiswave’s fifth button, instead of using a kick harness.
Therefore, if you want to add permanent CPS and MVS/AW support to your cab, you will need to add some custom wiring!
What are these controls inside the machine?
Most cabs will have a few controls inside the main door, situated near the power supply. There is usually an internal on/off switch as well as an external one, a volume knob if your cab has a built in amplifier, and some red buttons. One of these is likely to be degauss (see “What is degaussing”). One will be the “test” button, used to access a games “test/service” menu for changing settings, and one will be “service”, a button largely used by SEGA for menu navigation. The service button will often act as a credit button in game as well.
You will probably also see a fuse, some extra connectors for various power options and a hole for 5V adjustment on the power supply. This should only be altered if you are having power issues with certain hardware and you should always use a multi-meter. Search our technical section for more info.
What about credits?
Most PCBs have a Free Play option, selectable either in the test menu or via dip switch. For those that don’t, you have several options; Some games coin up with a press of the service button, you can get hold of some 100 Yen coins, fit a credit switch, or you can even open up the coin mech door and flick the spring that recognizes credits. It's even possible to modify a Japanese coin mech to accept 10 and 20p pieces.
So how would I go about swapping games then?
The procedure for installing a standard JAMMA PCB goes something like this:
- Fix your PCB to the wooden mounting board.
- Open the door and attach your PCB to the JAMMA harness.
- Power up the machine. Insert a credit to get the game going and adjust the volume pot on the PCB to the required level with a small screwdriver. (It may be handy to keep the PCB outside the machine for this.)
- Enter the test menu, either by pressing the test button inside the machine or by pressing the appropriate button or dip-switch on the PCB. Set up your game, I.e. Free Play, Demo Sound on or off, game settings etc.
- Adjust the picture using the monitor pots. Most test/service menus have dot-cross-hatch and R,G,B level screens for this purpose but it’s sometimes easier to adjust whilst the game is running.
- Add any artwork to the instruction space and marquee and lock your machine up again.
And that’s all there is to it!
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