A Game Development Blog by Nickolas Marentes for the Tandy Color Computer 3.

      This blog will primarily focus on the creative and technical design aspects I employ to create this game.
      Due to time constraints, I will not be delving into the actual coding details.


Chapter 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.

In 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 animated.

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 or Mac.

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.

To 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.




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.

Copyright 2021 by Nickolas Marentes