Title says it all...
I'm making a game in ASM, but I'm really new to programming, and I can't make a proper working piece of scipt that scrolls sprites down the screen.
I'm making a guitar-hero like game, where "O" start at the top of the screen, scroll down at a certain speed, and when the "O" matches an "O" in the bottom of the screen, you must press a certain button.

Requirements are:

- It must be possible to drop down some "O" sprites in a specific order, not just randomly. So I can determine the time between each "O" falling down.
- While the "O" is dropping, the Calc must still respond to a keypress, and execute a script when a button is pressed (to see if you pressed the right button at the right time, and increase/decrease score accordingly).

I hope I've been clear about what i'm trying to do.
If anyone could help me out by giving tips, or making a small script that performs a piece of what I want, it'd be a great help!

Thanks in advance!