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Intuitive Discursion - Mega Fun Pack update: Space Patrol
or Discursive Intuition?
Mega Fun Pack update: Space Patrol
I guess it's been nearly a week since I last updated. I've been reading daily, but I haven't had much time/energy to post. In fact, actually, my sleep schedule has been pretty whacked out the past few days. Ick.

In the last couple weeks, I started getting back into writing Space Patrol. Space Patrol is a video game I've been developing off and on for the Intellivision video game system. The game is similar in concept to the classic Moon Patrol. Growing up, I had the TI Home Computer version of the game. The Intellivision never had a version. So, I figured I'd try to make my own homage to the original on that system.

Space Patrol expands the original Moon Patrol concept. In the original, you drove your buggy around on one of two courses on the Moon. The two courses were named "Beginner" and "Champion." Each course had 26 checkpoints and divided into 5 stages: A-E, F-J, K-O, P-T, and U-Z. Space Patrol keeps the checkpoint and stage structure, but adds 3 new celestial bodies to the mix. Now you can shoot at aliens on four worlds, each with two patrols: Moon, Mars, Pluto and Mercury. Mars, Pluto and Mercury each feature similar game play to the Moon, but with different layouts and different aliens.

The different worlds also look unique:





That last one is an underground scene. That's right, I'm putting tunnels on Mercury. :-) Space Patrol also features the parallax that made Moon Patrol stand out. For example, here's how that underground scene looks animated:

(It actually looks smoother on the real system. GIF animation has its limits.)

Now, keep in mind, I'm doing all this with a 895kHz processor. I only get about 2000 instructions for each screen refresh. It's tight. So, I spent the last week optimizing out about 500-600 cycles from my per-frame duties and about 8-10 words from my stack usage, bringing it down to 16 words. (Those of you who know programming: Yes, I'm using only 16 words of stack. I'm trying to get down to 12, which is difficult when the hardware imposes a minimum of 8 for its own use.) I now seem to be meeting all my timing constraints and am not overflowing the stack. w00t! And, right now the whole game fits in about 26K bytes. The final game (with all 4 worlds) will need to fit in 32K bytes. Tiny, isn't it?

David Harley has been helping me with this. He's not writing any code, but rather he's developing the levels people will play in the game. He's also tweaking the control programs for the saucers, trying to manage the difficulty and the fun of the game. He's put in the Moon Beginner and Champion courses so far, and we've started play testing them. Real progress at last!

So that was a big part of where I've been spending my brain cells. Also, two Fridays ago, Oct 6th, I managed to crunch my car. Nobody got hurt—it was a pretty stupid accident—but that means I've been without my car, again, for another couple weeks. I swear, I'm not allowed to drive that car! :-P $DEITY (or @DEITY if you're polytheistic) and the Universe must be conspiring against me...

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mr_z From: mr_z Date: October 17th, 2006 05:35 pm (UTC) (Link)
That'd be Parsec™, one of the top selling games of 1981 or 1982, IIRC. If you had the Speech Synthesizer, it'd say in a friendly female voice "Press Fire to Begin," "Ships Attacking" and would count down from 10 to 1 when you were in the asteroid belt.

No, I've never heard of it. ;-)
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