TIME PILOT ARCADE MACHINE HOW TO
TIME PILOT ARCADE MACHINE CODE

The chip also has one complex volume (envelope) control circuit that can be configured to control a Multiple voices, but the frequency is the same on all of them.Įach voice has an independent volume control register. But the NOISE base frequency is controlled with a separate register. The voices have independently controlled frequencies. A mixer register configures each voice as either a TONE, or NOISE, or off. The AY chip provides three independent voices labeled A, B, and C. Jungle Hunt, Scramble, Spy Hunter, Time Pilot, Tron, and Two Tigers to name a few. You have heard the AY voices in classics like 1942, Frogger, burger Time, Journey, A sound board often used multiple AY chips. The General Instruments AY-3-8910 sound chip was popular in arcade games and computers in the 80's.

TIME PILOT ARCADE MACHINE CODE

The hardware allowed the code to change the frequencyĪnd the volume of the channels independently. The sound board processes music scripts.Įarly arcade sound hardware provided a number of channels - one channel for single playing sound effect. The sound board manages all the simultaneous effects as the

TIME PILOT ARCADE MACHINE HOW TO

The sound board decides which effects have what priority and how to schedule simultaneous sounds. The main game board sends requests to the sound board to start/stop effects. Most arcade games use a dedicated sound board with its own CPU and sound-effect code.

Sound isĪn integral part of the code from the beginning. Sound effects are not something that is just added to the code later as to spice it up. Momentarily and then restarted? Resource scheduling is tedious. Can a continuous sound (like music) be interrupted What sound effects are currently playing and decide whether to preempt one or to ignore the new sound effect.

When a sound effect needs to be played the code must look at Only so many effects can be playing at any one time. There are usually limited sound resources. Different instruments also play different rhythms of notes at the same time.įor instance, a base groove running beneath a main melody. Music usually plays as multiple notes (instruments) at the same time (harmony). Notes have volume envelopes an instrument attacks a note hard but the note slowly (or quickly) fades with time. Notes have complex waveforms with inherent harmonics (trumpets and flutes sound veryĭifferent when playing the same note). Truck notes are not just pure sine waves that start and stop abruptly. Musical notes are played at precise frequencies with precise timing. Music is the most complex sound effect of all. But a quarter of a second is a long, long time in the The game code mustĬhange the volume and frequency of this effect from start to finish, which may not seem like a big deal. The effect itself is mostly white noise (a random spread of frequencies), but the average frequency of the noise decays with time as well. The effect starts loud and decays away to nothing by the end. Imagine the quarter-second sound of an alien exploding. The code starts them up and stops them manually when the game object is removed. These effects usually take longer than a second and are often continuous.

Examples include a racecar motor, a falling bomb, and a mother-ship traversing the screen. These effects take a fraction of a second, and the code simply starts them and lets them run to completion.Īn ongoing effect is the continuous sound of a game object. Examples include a laserįiring, a frog jumping, and an alien exploding. A one-shot sound is the audio record of an event. Most sound effects fall into one of two categories: one-shot and ongoing. All three boardsĪre disassembled on this site: Frogger, Time Pilot (both by Konami), and Moon Patrol. In this dig we'll explore the sound effects and music of the Time Pilot game.īut first I'll compare the code of three different sound boards and see how each approached sound in a slightly different way.

Time pilot arcade machine