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Cart #saucerinv_nosnibor28-0 | 2020-01-05 | Code ▽ | Embed ▽ | License: CC4-BY-NC-SA

Submitted for Applecart. Thanks again, @dw817 for the fun challenge! Also thanks to @chizel9000 for the helpful feedback on the WIP.

Saucer Invasion is a game in which you shoot missiles at flying saucers. You can move the silo horizontally across the bottom of the screen and fire vertically at your foes. Your score for hitting a target is based on its height and speed, and there's a penalty for missing. The game ends when you run out of either time or ammunition. This is explained in a big ol' wall-o-text intro at the beginning, in keeping with the spirit of the original 1977 Apple II game that served as inspiration.

Updates from the WIP version:

  • Flying saucer Y movement is smoother. Instead of jittering randomly, the saucer picks a target Y value and moves toward it. When it reaches the target Y, a new target is randomly selected. This actually makes the game harder, in my opinion!
  • Smaller missile. Original missile was 8x32 in its first stage and 8x16 in the second stage. This looked awkward, so I shrunk it to 8x24 and 8x12.
  • Two graphics modes! Select DEFAULT or CLASSIC graphics from the title screen. DEFAULT uses my new sprites, while CLASSIC draws the elements each frame using LINE and RECTFILL (just like the good old days).

Have fun! :-)

P#71767 2020-01-05 02:56

:: dw817

I certainly don't want to leave you hanging, @Nosnibor28. I will definitely be posting a new page for the Applecart series figuring your cart (this very one) prominently a little later today.

If you're curious, the Apple was definitely too slow to use lines to draw what it needed. Instead this particular game is a combination of INTEGER Basic and 6502-assembly. In that it would use 6502-assembly to poke directly to the HIRES Page 1 to make its images appear.

It's slow because INTEGER Basic was originally designed for LORES graphics, that is a display of 40-pixels across by 40-pixels down, 16-colors, with room for 4-lines of text at the bottom.

Thanks so much for contributing !
Once again, another Gold Star for you.

P#71778 2020-01-05 17:39 ( Edited 2020-01-05 17:53)

gr8 work!

P#71784 2020-01-05 21:46

Interesting stuff, @dw817. I don't think I ever touched the original Apple II. By the time I was in school and got my hands on a keyboard, we were using the Apple IIgs, which likely had a bit more horsepower.

P#71793 2020-01-06 17:23

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