Space Invaders (for ZX Spectrum/TS2068/TC2068)

Version 1.0

- Initial Version

Version 1.1

- Game syncronized at 50hz

- Fix saucer/UFO speed

- Fix player shot speed

- Fix alien shot speed normal, and when less of 9 aliens (bit faster)

- Smooth alien shot animation

- Add sounds BeepFX based for "BEEPER" Sound (original BeepFX player by Shiru http://shiru.untergrund.net)

- Add AY Sounds (Fuller Box, Sinclair 128k)

- AY Sounds from and made with AYFXEdit (https://zx.remysharp.com/audio/)

- Autodetect Sound (Beeper, FullerBox, Sinclair 128k)

- If only 1 alien left, move a bit faster from left to right, as original

- Fix no delete right arrow in configure menu when players control reach the limit

Version 1.2

- Add ZX81 Version (require zxpand or rampack 32k)

- Now aliens move one at a time

- Fix aliens score

- [ZX81] wrx support

- [ZX81] chroma-81

- [ZX81] zxpand joystick support

Version 1.3

- Fix gameplay 2 players

- Re-code lot of functions to ASM

- General better speed

- [ZX81] AY-Sound + Full Chroma-81 Support

- [ZX81] Full version, look as ZX-Spectrum version

- Fix other minors bugs

Version 1.3+

- Reduce alien step sound volume to 50%

Version 1.4

- TS2068/TC2068 Support

- Sprite rutines optimization

- Fix sound detection

Version 1.4.1

- TS2068/TC2068 Joystick Support

Source Code: https://github.com/SplinterGU/SInvaders