Upgrading sound effects and redefinable keys

Upgrading sound effects

While working on Harrier Attack Reloaded, I was able to develop my own sound effect system to increase the types of sound that could be produced by the AY chip. This allowed me to specify sound effect duration, volume fades and tone changes over time, as well as repeat sounds when they have finished playing. My sound system uses the Z80 interrupts, which makes this possible. Before in Mimo's Quest, I was just using the AY's own functions to produce very basic noises. Hopefully over the next few weeks I will be able to create more interesting sound effects for the game.

Redefinable keys

In Harrier Attack Reloaded, I also used the interrupts to scan the keyboard every 50th of a second. Scanning the entire keyboard in the interrupt means I can easily check what keys have been pressed very quickly at any point in the game. This also enabled me to create a function to redefine the game keys. I have reworked this sound and interrupt code back into Mimo's Quest, and over the next week or so, I will create a function that will allow the player to redefine the keys so the game can be played by keyboard or joystick.