Pinball sound systems
Modern solid state pinballs have a carefully designed sound canvas including music, speech and sound effects. The game comments and instructs player by telling what to shoot for. But even in the old EM machines there were sounds present other than just clicking of relays. As early as 1933 there was a sound effect in pinball. Harry Williams's Contact had a bell that was hit by a ball going to a hole. Considering that this was the first machine to have an electric device moving the ball, it must be noted that Contact was quite an advanced machine! When the electromechanical score counters came into use, they often had a lever that stroke a bell in step with scoring. That soon evolved into two-bell system, where 10.000 points sounded one bell and 100.000 points another. Of course the replay knocker was present already then, making the rewarding noise when player scored a replay.
In the 1960's, score reels replaced the advancing light scoring. Also score inflation was reduced by removing unnecessary zeros from the score. Accompanying the score reels was a three tone chime box, where a solenoid hits a metal bar with plastic head plunger, making quite nice sounds. The lowest chime was usually connected to 1 point scoring, next one for ten points and the high chime for 100 points. Not all machines had a three note chime, some used only one bell. On some Bally games, a plug could be moved from one hole to another in the backbox to select what score reel rings the bell. In this golden era of pinballs, noise and atmosphere at the arcades were quite high when tens of pinballs played their chimes.
The first solid state machines had a similar chime box. But now there weren't any relay clicks anymore, although Williams's first SS games had a single scoring reel hidden inside the game to confirm scoring to player. It was feared then that the players would not like a machine that doesnt make clicking noises, but fortunately that did not happen and the noise reel did not stay in use for long. The mechanical chime box had one shortcoming. Its volume could not be adjusted. Some operators damped the sound when the location demanded a quieter game, but most of them just disconnected the chimes. The game was totally silent then. Hardly fun to play anymore.
Because electronics had already replaced mechanical score counters and relays, it did not take long before also the chimes were replaced with electronic sound boards. Gottlieb's System 1 game Close Encounters was equipped with "new space age sound", or a three tone beeper, to be precise. Three square wave oscillators made of 555 timers and an LM380 amplifier made lots of sound, if not so beautiful then at least new. The principle was as before. 10 points made a low beep, 100 points a little higher and 1000 points a high pitched beep. The volume was now adjustable. The three tones combined to very modest memory capacity of those games were not suitable for music playing, only very simple tunes could be heard at coin insertion and game starting. Bally and Williams skipped this simple sound board phase and started with much better systems. The Bally board could make better waveforms instead of harsh square wave, and it had an envelope generator to make sounds more chime-like. The Williams board made either chime tones, or quite strange bubbling sound effects, depending on switch setting.
Soon the microprocessor found its way into sound cards. Gottlieb's System 1 games starting with Totem had a board with 6504 CPU, that could generate various sounds with an 8 bit D/A converter. Also these boards had two different sound sets that the operator could select by switch setting. Of course, Williams soon followed, adding a revolutionary feature to its board. That was the MC3417 CVSD decoder, sort of D/A converter that could generate sound with less memory capacity than plain DAC. With the CVSD, mechanical sounding but still intelligible speech could be produced. Williams's Gorgar was the first talking pinball with a vocabulary of 7 words, but they could be combined to form many sentences. Bally took a different way for its talking games, and used a Texas Instruments TMS5200 chip, that produces speech with even less bit rate than CVSD. But the CVSD could also make sound effects, when the Texas chip only produced speech. An interesting game was Bally's Centaur, where there was an analog shift register echo circuitry, or "Say It Again" module connected to the TMS5200 board, to make a dramatic echo to the speech. And we all remember Bally's Xenon, the first pinball to talk with female voice.
Bally developed a new sound board that used a 16 bit 68000 CPU to play music and effects, and of course also speech. Williams stayed with 8 bit 6809 CPU and an FM synthesizer OPL2, familiar from early PC soundcards, and of course a CVSD. The OPL made music, CVSD generated speech and other noises came from an 8 bit D/A converter. This system was used until it was
replaced by a DSP processor based board. It used an Analog Devices ADSP2105 DSP to play digitally compressed samples in 6 channels. The board was called DCS for Digitally Compressed Sound and first used in Indiana Jones. Actually, Twilight Zone was supposed to be the first DCS game but the board did not get ready in time.
http://tuukan.fliput.net/sound_en.html (more on link)