At last ..... an update for Galaforce for the Acorn Atom.
I added FX-sounds and music.

The TODO list is now:

- Adding Joystick support
- Testing levels/patterns

You can find a video at: http://www.youtube.com/watch?v=tsaApN-uG-U

Greetings
Kees

Wow. That sounds amazing! I love the initial tune before the game starts!

Your ports just keep getting better and better, Kees.

Sam.

Some fast and furious gameplay there! The sounds are interesting: I see you generate the waveforms yourself - very impressive!

Perhaps also worth reminding people that Kees is doing a sterling job of keeping his Atomic Galaforce development diary up to date, which is a fascinating read.

Sam.

Thank you ... .. but on an Atom it's a necessary evil to get sound.
The Atom only has a beeper connected to a bit so generating sound is not easy and takes a lot of CPU time.
I am testing to generate 2-voice sound with programming the 6522 VIA to relieve the processor.

Channel1:
Program the shiftregister to shift out continuous patterns using T2 on CB2.
You can write 00001111 or 00110011 or 01010101 to get a squarewave

Channel2:
Program T1 to generate continuous squarewaves on PB7

Connect the 2 bits together (with a resistor) and feed it into an amplifier.
This way you only have to change T1, T2 or the shiftregister to get a different note without consuming CPU time.

Should also work on a BBC

Greetings
Kees

Two channel sound on an Atom? Now that would be something!!