Evel Knievel had four chime bars and there must be some that had five.
Indeed! I asked Arngrim about it, and he mentioned Black Jack as another 4-chime game. Marco Specialties has a rebuild kit for the "Bally 4 bank" chime unit, so it evidently was a standard part used in a run of games. Interestingly, looking at their diagram, it was actually two separate units: a 3-bar unit and a 1-bar unit, where the extra bar looked like it was roughly the same size as the large bar of the 3-bar unit. Maybe it was a different metal composition to produce a different tonal quality or something. Anyone know what that actually sounded like?
5-chime games might be in doubt, at least as far as the late EM/early SS era goes. Arngrim's example of a 5-chime game is Stellar Wars, which does indeed have "Sound 1-5" listed in the solenoid table. But a closer look at the operator's manual reveals that the game didn't come with a chime unit at all. It came with an electronic sound board, with speaker output. I think this must have been during the transitional phase where they switched over to electronic sound boards. Here's my wild guess: they wanted to switch from chimes to electronic sound boards, to save a few bucks and to give players a more modern experience, to compete with video games. But they were still using MPU boards that only had solenoid outputs, and no data port to send commands to a sound board, like the modern MPUs have. Traditionally, a few of the solenoid outputs were dedicated to drive chime solenoids. So they designed a sound card that acted as a drop-in replacement for the chime unit, taking solenoid-level inputs as its data inputs to trigger 4-5 different sound effects. Pair the new sound card with the old MPU and you have an electronic-sounding game. (Youtube videos of Stellar Wars in action confirm that it uses electronic sound effects. If I had seen the videos in isolation, I might have thought that they represented retrofits where people had replaced their chime units, but the operator manual doesn't seem to suggest that chimes were ever an option for original equipment for this title.) Another title that Arngrim mentioned, Disco Fever, appears to have exactly the same setup, but with four "sound" solenoid outputs connecting to a sound board. I'd guess that a number of Williams System 3-4 games from 1978-79 share this design. So anyway, while there do seem to be some games with 5 "sound" solenoid outputs, it doesn't look like they were ever connected to actual chimes.
Based on all of this, I think my new revised ideal schema for the DOF layout, if I were starting from scratch, would be something like this:
Chime (High Tone)
Chime (Mid Tone)
Chime (Low Tone)
Chime (Even Lower Tone) --> ? to be revised if anyone can come up with a more informed description of the tonal quality
Shell Bell (small)
Shell Bell (large)
I'd add the shell bells as separate toys for the sake of fanatical cab builders who wanted to add authentic Bally 1970s style bells a la Fireball. Most cab builders would just map those to Chime (High Tone) and Chime (Low Tone).
Edited by mjr, 01 June 2019 - 08:11 PM.