04 - Let's make some noise!
In the last chapter, I showed the Spinning Cogs Background effect providing a visual ambience that gives the game a factory feel.
In this chapter, I have also added an audible ambience
to further heighten this effect. The volume level is kept low so it
doesn't distract in the game and allows the other foreground sound
effects to be heard above this ambience.
the video from the last chapter, the sound routine was actually
running and being triggered off the CoCo3's GIME FIRQ Interrupt, driven by
the Programmable Timer at 7000Hz. The only reason there was no sound in that video was because it had no sound samples to play.
Adding the Samples
For this chapter, I have provided sound samples and configured the code
so that I can test any of the samples by pressing the number keys on the keyboard while the cog background is being
Back in the good-ol'-days,
I would obtain sound samples by sampling sounds on my CoCo that I had recorded on
cassette. Nowadays, we can find any sound we
want by downloading a free WAV or MP3 file from the internet on our modern PC
I have currently added 11 samples using up a total of 49K of RAM. I may add more
later if the need arises but these 11 samples should cater for most
situations initially. The sound routine can play two samples simultaneously as two sound channels with
one channel designated to playing the Cogs Sample in a repeating loop to create the ambient
background drone of the cog motors.
import and arrange the samples into the CoCo3, I wrote a program in
standard ROM BASIC I called MakeSND which creates the files ready for
loading into the game.
Click on the video link below to see a demonstration of the various sounds I have chosen.
MAKESND - WAV IMPORT
CLICK IMAGE FOR VIDEO PREVIEW
Coming up next chapter
Next is to finish creating 3 more cog backgrounds so that I can vary the background in each of the levels.
Then, I'll get a Title and High Score page up.