What Is a JAMMA Arcade PCB? JAMMA vs. Pre-JAMMA Classic Arcade Hardware

By HighScoreSaves Technical Team

Reviewed and updated August 22, 2026

JAMMA is one of the most important wiring standards in arcade hardware. It allowed many arcade game PCBs to use a common cabinet connection for power, video, audio, controls, coin inputs, and other basic functions.

Earlier classic arcade games usually predate JAMMA and commonly use manufacturer-specific or game-specific wiring. A Pac-Man, Donkey Kong, Frogger, Galaga, or other early classic arcade PCB cannot be assumed to use JAMMA simply because it is installed in a cabinet that has later been converted to JAMMA wiring.

Understanding the difference matters when identifying a PCB, moving boards between cabinets, choosing adapters, troubleshooting wiring, or determining whether an original-hardware upgrade is compatible.

This guide explains what JAMMA is, what a JAMMA edge connector carries, how JAMMA differs from pre-JAMMA dedicated wiring, what JAMMA adapters do, and why a cabinet being wired for JAMMA does not change the identity of the PCB installed inside it.

What Does JAMMA Mean?

JAMMA refers to the arcade-industry wiring standard that became widely used beginning in the mid-1980s.

Its major advantage was standardization. Instead of every game requiring a completely different cabinet wiring arrangement, compatible game boards could share a common connection for many essential signals.

This made it much easier for arcade operators to replace or convert games without completely rewiring the cabinet every time the PCB changed.

What Is a JAMMA Edge Connector?

Standard JAMMA uses a 56-contact PCB edge connection, with 28 contact positions on each side of the board edge.

One side of the connector is conventionally identified with numbers and the opposite side with letters.

Through that edge connection, the cabinet can provide or receive the major signals needed by a typical compatible arcade game.

These include:

Ground
+5V power
+12V power
Other supported power connections where applicable
RGB video
Video sync
Audio
Player 1 controls
Player 2 controls
Start buttons
Coin inputs
Service and test functions
Coin-counter and related cabinet signals

Not every game uses every available connection.

What Is a JAMMA Harness?

The JAMMA harness is the cabinet-side wiring that connects the JAMMA edge connector to the rest of the arcade machine.

Individual wires run from the connector to components such as:

Power supply
Arcade monitor
Speaker
Joysticks
Control-panel buttons
Player-start buttons
Coin switches
Service switch
Test switch
Coin counters or other supported hardware

The harness is therefore part of the cabinet wiring. It is not the game PCB itself.

What Is a JAMMA Arcade PCB?

A JAMMA arcade PCB is a game board designed to connect to the standardized JAMMA cabinet interface, or one designed to be sufficiently JAMMA-compatible for the intended installation.

When the PCB and cabinet are correctly wired to the same standard, the operator can connect the edge connector and route the supported power, video, audio, and control signals through that common interface.

That does not mean every JAMMA game has identical hardware. CPUs, ROMs, graphics systems, audio hardware, board layouts, game programs, controls, and other circuitry can be completely different.

JAMMA standardizes an interface. It does not standardize the entire game board.

What Is Pre-JAMMA Arcade Hardware?

"Pre-JAMMA" is a convenient term commonly used for arcade hardware that predates or does not use the JAMMA wiring standard.

Early classic arcade manufacturers designed games around their own hardware platforms and cabinet wiring arrangements. A board might use its own card-edge pinout, multiple connectors, separate power plugs, ribbon cables, audio connections, or other game-specific wiring.

Two early arcade PCBs may have edge connectors that look similar while assigning completely different electrical functions to those contacts.

Physical fit is therefore never proof of electrical compatibility.

Why Was JAMMA Important?

Before standardized wiring became common, converting a cabinet from one hardware platform to another could require substantial wiring changes.

A standardized interface made compatible game changes easier because many essential cabinet connections remained in the same locations.

This was especially valuable to arcade operators who routinely changed games to keep locations fresh and profitable.

Does Every Arcade Game Use JAMMA?

No.

Many of the most recognizable early classic arcade games were designed before JAMMA became common. Other later games also use proprietary connections, extensions, additional harnesses, or hardware that is not fully described by the basic JAMMA interface.

Never assume a board is JAMMA based only on its age, cabinet style, edge-connector shape, or the fact that it is an arcade game.

Is Every 56-Contact Edge Connector JAMMA?

No.

Connector size alone does not establish the electrical pinout.

The function assigned to each contact is what matters. Applying power to an unidentified PCB because its connector appears to fit can damage original arcade hardware.

When a PCB is uncertain, identify the board first.

HighScoreSaves explains the process in How to Identify Your Original Arcade PCB Before Ordering a Kit .

JAMMA vs. Dedicated Wiring

A dedicated classic arcade cabinet was normally built around a particular game or hardware platform.

Its wiring may connect the original PCB directly to the cabinet's controls, monitor, power system, coin door, speakers, and other components using the manufacturer's original pinout.

A JAMMA cabinet uses a standardized harness for the common JAMMA functions.

The difference can be summarized simply:

Dedicated wiring: designed around a particular game or hardware family.
JAMMA wiring: designed around a common arcade interface used by many compatible boards.

Can a Pre-JAMMA PCB Be Used in a JAMMA Cabinet?

Often, but only with the correct adapter and compatible cabinet hardware.

A properly designed adapter translates the original PCB pinout to the corresponding JAMMA cabinet connections.

For example, the adapter may route the appropriate original-board contacts to JAMMA power, video, audio, coin, start, joystick, and button connections.

The adapter must be designed for that specific board or compatible hardware family. A generic physical connector is not enough.

Does a JAMMA Adapter Make the Original PCB a JAMMA PCB?

No.

This distinction is important.

If an original pre-JAMMA arcade PCB is connected to a JAMMA cabinet through an adapter, the PCB remains its original hardware type.

The adapter changes the connection between two wiring systems. It does not redesign the original board or change its CPU architecture, ROM layout, memory map, timing, or game hardware.

Can a JAMMA-Wired Cabinet Contain a Pre-JAMMA Original PCB?

Yes.

A cabinet may have been rewired or converted during its life. It could contain a JAMMA harness connected through an adapter to an original pre-JAMMA game PCB.

Conversely, an original cabinet may have been modified to accept newer boards.

This is one reason cabinet artwork and wiring alone cannot establish which game PCB is installed.

What Is a Conversion Cabinet?

Arcade operators have converted cabinets from one game to another for decades.

A conversion can involve changing:

The arcade PCB
Wiring harness
Control panel
Marquee
Bezel
Side artwork
Monitor orientation
Power supply
Controls

As a result, the game visible on the screen, the artwork on the cabinet, and the hardware mounted inside may come from different periods or manufacturers.

For upgrade-kit compatibility, identify the actual PCB rather than relying on the cabinet exterior.

JAMMA Does Not Guarantee Complete Control Compatibility

The standard interface handles a common set of controls, but some games need more inputs than the basic JAMMA arrangement provides.

Games using additional action buttons, unusual controllers, trackballs, steering controls, light guns, analog controls, four-player inputs, or other specialized hardware may require additional connectors or separate wiring.

The presence of a JAMMA connector should therefore never be interpreted as proof that every control required by every JAMMA-era game is available through the main harness.

What Is JAMMA+?

"JAMMA+" is an informal term commonly used for systems that use the main JAMMA interface plus additional wiring for controls or features that are not provided by the basic standard.

A common example is an auxiliary button harness used by games requiring additional player buttons.

Because these extensions are hardware-specific, always use the correct documentation for the game and PCB.

JAMMA and Original Arcade PCB Upgrades

Whether a cabinet is JAMMA does not determine whether a HighScoreSaves kit is compatible with the game PCB.

HighScoreSaves upgrades are designed around specific supported original arcade PCB hardware. Compatibility can depend on factors including:

Original PCB type
Board revision
Main CPU
CPU socket
ROM configuration
Adapters
Previous repairs or modifications
Game-specific hardware

A JAMMA adapter between the cabinet and board does not eliminate those requirements.

Read How High Score Save Kits Work on Original Arcade PCBs for a detailed explanation of original-PCB upgrades.

Original PCB vs. JAMMA Replacement Board

A modern replacement board can have a JAMMA connector and play a classic arcade title, but that does not make it the same hardware as the original PCB.

Likewise, an FPGA platform, software-emulation board, multigame computer, or reproduction PCB may connect to a JAMMA cabinet while using a completely different internal architecture.

The connector standard and the hardware architecture are separate questions.

For a detailed comparison, see Original Arcade PCB vs. Replacement or Emulation Board: What's the Difference? .

Bootleg and Reproduction Boards May Also Use JAMMA

A bootleg, reproduction, or replacement PCB can be designed with a JAMMA-compatible edge connection.

Therefore, seeing a JAMMA connector does not prove that a board is an original factory PCB.

Original-hardware identification must consider the complete board: manufacturer markings, PCB numbers, layout, CPU, ROMs, revisions, daughterboards, repairs, and other identifying features.

If the board is uncertain, see Will an Arcade Upgrade Kit Work on a Bootleg, Conversion, or Reproduction PCB? .

Never Use the Edge Connector as a Compatibility Test

Do not plug an unidentified board into a cabinet merely because the edge connector appears to fit.

Incorrect power or signal routing can damage the PCB, cabinet electronics, or both.

Before connecting an unfamiliar board:

Identify the PCB.
Confirm the connector pinout.
Confirm the cabinet wiring.
Confirm connector orientation.
Check for adapters or conversion wiring.
Verify required power.
Inspect the connector for damage or modifications.

Edge-Connector Orientation Matters

A connector installed in the wrong orientation can place power on contacts that were intended for completely different signals.

Some connectors and boards include keying intended to help prevent reversed installation, but never rely on keying alone when working with old, converted, repaired, or modified arcade hardware.

Document the original connection before removing a PCB.

HighScoreSaves covers safe board removal and connector documentation in How to Safely Remove and Reinstall an Original Arcade PCB .

JAMMA vs. Pre-JAMMA at a Glance

JAMMA: standardized arcade cabinet interface used by many compatible boards.
Pre-JAMMA or dedicated: manufacturer-specific or game-specific connection system.
JAMMA adapter: translates wiring between a non-JAMMA PCB and a JAMMA cabinet.
JAMMA cabinet: cabinet wired around the JAMMA interface.
JAMMA PCB: board designed to use the standard interface.
Original PCB: describes the identity of the game hardware, not merely its cabinet connector.

How to Identify What You Have

When inspecting an unfamiliar arcade cabinet, do not stop after identifying the wiring harness.

Photograph:

The complete component side of the PCB
The complete solder side
The PCB edge connector
Any JAMMA or game-specific adapter
The CPU area
ROM labels
Manufacturer and board numbers
Revision markings
Additional control harnesses
Repairs, jumper wires, or conversion modifications

That information provides a much more reliable picture of the actual hardware than the cabinet artwork or connector shape alone.

Related HighScoreSaves Arcade Knowledge

Learn More About Classic Arcade Hardware

JAMMA solved an important cabinet-wiring problem, but it is only one part of understanding arcade hardware. The PCB itself still contains the processor, ROMs, RAM, graphics hardware, audio circuitry, connectors, and game-specific components that define how the original game operates.

Visit HighScoreSaves Arcade Knowledge & News for additional technical guides covering original arcade PCBs, hardware identification, installation, troubleshooting, Free Play and High Score Save Kits, multigame upgrades, Wi-Fi leaderboards, and arcade preservation.