Latest revision as of 04:43, 3 January 2021


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1 Introduction

Most modern game systems have a free play option available within the game's settings. However, older games do not always have an obvious way to enable free play. That being the case, the goal is (with the original boardset) to avoid having to install an extra switch / button on the outside of the cabinet or coin door and to avoid having to open the coin door.

There are a few different options depending on the game system:

Set the first replay score value to 10,000 (or whatever the lowest possible score is).
Add a stacked switch to the start/credit button switch.
Add a switch to the coin reject button.
System-specific wiring / jumper modifications.
Replace the game ROM with an EPROM with a modified version of the game code (typically known as a free play ROM or Home ROM). Some of these ROMs have additional fixes/features beyond just a free play option. Most MPUs will need to have some jumpers changed in order to accommodate an EPROM.

2 Generic Solutions

2.1 Stacked Switch

A stacked switch is the concept of adding a credit switch on top of the start button switch. Then when the start button is pressed, it triggers both the credit switch and the start button switch simultaneously in order to start the game. On games that do not have a built-in free play option, this is one method that can be used to add a free play feature without having to add any (permanent) exterior modifications.

Here is an example for a stacked switch for an early Allied Leisure Game.

Depending upon the start button parts and game system, the stacked switch parts and wiring may vary, but the general principles are largely the same.

2.2 Coin Reject Switch

The coin reject credit switch option is the concept of adding a credit switch that can be activated by one of the coin reject buttons. On games that do not have a built-in free play option, this is one method that can be used to add a free play feature without having to add any (permanent) exterior modifications to the game. So, when the coin reject button is pressed, it activates the credit switch, and adds a credit to the game. This usually works better on games with button-style coin rejects, rather than slot-style coin rejects.

Here is an example for adding a coin reject credit switch on a Viza War game.

Depending upon the coin door style and game system, the parts and wiring may vary, but the general principles are largely the same.

Another example on a Stern MPU-200 game: The leaf switch was positioned to make contact with the coin reject mechanism. Two holes were drilled in the bracket, and #5 sheet metal screws were used to attach the leaf switch. The switch was insulated from the coin reject mechanism to prevent grounding, although fish paper could be used instead. The wires for one of the coin switches were soldered to the leaf switch.

MPU-200 Coin Reject Switch Modification

2.3 Add-Ons

onecircuit.com/CoinUp - Designed for video arcade games, but might also be applicable to pinball machines. However, this device will not work with games that include the coin switches within a switch matrix.

2.4 Replay Score

This option may work when bringing games to shows more than in a home environment. Set a replay score that is very low so it can easily be achieved in order for a credit to be awarded. This is most common on classic Bally SS games where the replay can be set as low as 10,000, which even on simply plunging the balls is typically hard to not achieve.

3 Game Systems

3.1 Allied Leisure

3.1.1 Generation 1

Credit switch stack instructions

3.1.2 Generation 2

A game-specific free play option is not available.

3.2 Atari

3.2.1 Generation 1

No game-specific free play options available.

3.2.2 Generation 2

The MPU dip switch in switch section A, switch 6 will enable free play when set to "on".

3.3 Bally

3.3.1 -17/-35/-133 MPU

New ROM code with free play and additional fixes/features for various games.

TwoBits / Game Boards USA - Fix It module

~~Add-on coin door connector board~~ (NLA?)

3.3.2 Hybrid Games (-133 MPU)

On the MPU, setting dip switch 30 to "on" enables free play mode.

3.3.3 6803 MPU

In the menu settings, go to adjustment 42, and set the value to 65.

3.4 Capcom

A free play option is built into the game code. Set menu option B:10 to YES. Default is NO.

3.5 Data East

Setting Data East games for free play

3.6 GamePlan

On the MPU, setting dip switch 8 to "on" enables free play. The credit display will show 99 credits, credits will be subtracted until reaching 0, and then cycle back around to 99.

3.7 Gottlieb

3.7.5 System 3

A free play option is built into the game code. To access this option in a menu with Cue Ball Wizard and newer games, the tournament switch must be switched to ON. On earlier games, the setting varies (adjustment 27 on Lights Camera Action, but adjustment 29 on Deadly Weapon).