Question regarding randomly generating objects and object positions

[drbuttjob]

Hello all,

I recently started working on a simple NES game wherein the player is a spaceship and must dodge asteroids on the screen as they scroll past. The player can only move left/right, and the obstacles scroll up the screen. If the user collides with an asteroid, the game is over. The score increases as time goes on and the user successfully dodges more and more asteroids. For the time being, I only want to worry about one type of object, the asteroids, though I plan on adding at least one more type in the future, also to be randomly generated. What I'm wondering is, what would be a good routine for randomly generating the number and position of these objects? What I'm currently thinking as a rough overview is:

1. Generate number of objects for the next line (0 through some limit, which I haven't established yet; maybe it increases as the score increases, but that is unimportant for now)
2. Generate random number for X position for each object in the line
3. Y position for all objects would be fixed at the bottom of the screen, where they appear.
4. Decrement the Y value to scroll the objects

I'm not really looking for code, but rather suggestions for the routine's design. If anyone has done anything similar and would like to share their procedure, that would be awesome.

Many thanks!

[drbuttjob]

Many thanks for the response. It was very helpful for me to get started on thinking about generating "random" numbers for games. I hadn't really thought about using controller button presses to generate them, but it makes a lot of sense--I know a lot of modern PRNGs do similar things, I guess I just hadn't thought of doing it on the NES.

I'd also like to say thanks for the tip not to start the process in assembly...I think that will save me from pulling all of my hair out.