Fractional Speed

[LD]

This code is a "translation" from a 6502 code I have here, if you know a fast and most optimized way to make it, feel free to share, I'm still a newbie in 8048 programming.

Fractional movement/speed is useful for add gravity or acceleration during sprite motion.

The trick is add with carry. Not aways the carry will be set, not aways the player will move. When more you add, more often the carry will be set and faster the player will move.

This demo move the sprite up and down, the same code can be used for horizontal motion.
Press up or down to move, press fire button to stop the player.