RPM (ARC Driver)
|Rusty's POKEY Music|
RPM (Rusty's POKEY Music) was the name of the sound driver program and programming language that the composers at Atari Games used for their arcade and console music. The sound driver was initially coded by Russell "Rusty" Dawe, hence why his name appears in the name of the sound driver. The music had to be written in a special Music Macro Language called Music-V Language (pronounced Music 5). When Atari started developing unlicensed Nintendo NES games under the name Tengen, they converted the whole music engine to make music for the NES. Later, when Atari began using the YM2151 chip for music in their arcade games, Rusty, Dennis Harper, and Peter Lipson took the existing code and created RPM-2 which added support for the YM2151 chip so the sound quality would improve. Lisa Ching converted RPM to the Sega Genesis, but retitled it to LSD (Lisa's Sound Driver).
According to Brad Fuller, the audio system was designed to be "interactive", in that the music would alter itself in-game depending on the situation the player was in. Brad also stated that despite a MIDI conversion tool being made for the driver, it was never used, as the composers preferred the MML data entry as to take advantage of the sound chip, as opposed to MIDI's limited capabilities.
When Atari developed the CAGE audio system, Fuller converted RPM's language to the sound driver.
The Star Wars arcade game's source code was released, and contains the driver and audio files for RPM.