While working on Frantic, I wondered if the sprite driver could handle even more sprites if it didn't have a playfield to update. That lead to an experiment with 50 sprites, which was successful.
50 sprite experiment (not all are visible due to flicker)
50 is a handy number for the game Asteroids. It's progression of 1 Large -> 2 Medium -> 4 Small asteroids means the I can handle the worst case arcade scenario, which is starting a level with 12 large asteroids and not shooting any small asteroids until all the large and medium asteroids have been hit. 12 large asteroids -> 48 small asteroids, thus 48 asteroids + 1 ship + 1 UFO is the most sprites needed for Asteroids.
Player and UFO shots are handled by the missiles and ball. Up to 6 can be going at once, with 4 allocated to the player.
The experiment has progressed far enough along to now be shared in the homebrew forum.
Menu Options:
- Players (disabled): 1, 2, co-op and possibly tethered (like Space Duel)
- Style: selects vector or solid sprite set
- Level (disabled): kids, beginner, normal or advance
- Down (joystick): nothing, shields, hyperspace or 180(flip)
- Friction: yes, no (controls if ship slows to a stop by itself)
- Bonus Life: no, 5K, 10K or 20K
Here's a screenshot of the vector style graphics. The digit to the right is the reserve ship count.
Screenshot of the solid style graphics, the saucer has just been taken out.
Nathan Strum's signed on to do the graphics, what's in place is the (extra chunky) graphics I borrowed from Asteroids. Sound effects are mostly borrowed from Frantic, and will be revised in the coming weeks. And speaking of Frantic, yes, it's on the back burner again.
If you're playing this in Stella, be sure to turn on phosphor mode or the flicker will probably annoy you!
- open Space Rocks with Stella
- hit TAB for the in-game-menu
- select Game Properties
- Select the Display tab
- change Use Phosphor to Yes
- click OK
- select Exit Menu
- Reload the ROM (Control-R)
ROM for Harmony or Stella (version 3.5 or later)
spacerocks20120430.bin 32K
260 downloads
Edited by SpiceWare, Tue May 7, 2013 8:36 AM.

















