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GI: General Illumination Command, via the FAST Serial Protocol

FAST Serial Protocol: Overview & First Steps

This documentation section is about the FAST Serial Protocol (FSP) commands, which are the low-level commands a host computer sends to a FAST board. Most FAST Pinball makers do not need to know about these details, since the pinball game framework (such as the Mission Pinball Framework) handles this communication for you.

If you're writing your own game framework, read the overview of how FSP works and how to connect first.

General Illumination (GI) is handled in a variety of different ways depending on the platform. Older pinball machines (System 11 and prior) typically used relays to turn groups of lamps on or off. (Regular coil drivers are used to control these. See the DL: commands). System 89 and 95 use special drivers that synchronize with the incoming power line frequency to create a method of dimming. New FAST controllers use LEDs and specific smart LED drivers to accomplish general illumination. The set of drivers described in this section only apply to System 89 and 95 that use the special GI drivers that can dim each channel. Most machines that have these drivers have 5 channels. Basically 5 groups of lamps that can be individually controlled. Typically 2 of the 5 channels are for the playfield, 2 in the backbox, and the fifth channel varies from game to game. In some cases 

The Driver created for General Illumination for

  • GI Set General Illumination Level

Note: On some machines, GI:7,FF will enable the Flippers.


Which GI channel, 0 to 7

If GI channel is on/off (relay), intensity 0 = off, else on.

If Triac channel, intensity = dim intensity 0xff = full on.

Documentation Feedback? Requests? Confused?

Hi! I'm Brian, and I'm responsible for the documentation at FAST Pinball. If you have any feedback, requests, corrections, ideas, or any other thoughts about this documentation, please let me know! You can email me at Thanks!

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