Re: [stella] Distella/Maze Craze problem

Subject: Re: [stella] Distella/Maze Craze problem
From: Paul Slocum <paul-stella@xxxxxxxxxxxxxx>
Date: Sat, 09 Feb 2002 13:14:08 -0600

Which Editor are you using?
Both Ultraedit & Textpad, even M$ Wordpad can handle
these files.

I use programmer's file editor. I managed to get it into Wordpad which is how I got the kernal. Part of the source was missing and I thought Distella ate it, but I must have mangled it myself trying to get the spaces out. Thanks for fixing it. I don't know why I didn't try search/replace.


Say, since I'm planning to port Sword Of Fargoal after
I'm done with Star Fire, I'm very interested in the
inner workings of Maze Craze, too. So, once you're done
with it, could you eventually post your findings, if
they resulted in a (even partial) reverse-engineering?

Absolutely. This stuff is probably second nature for you guys who have been programming 2600 longer, but I was impressed with Maze Craze doing a full asymmetrical playfield while drawing both players and the missiles and ball. And it's done flicker-free with smooth movement between maze lines.


One of my big questions was how he displays 23 lines of a randomly generated playfield maze. 23 * 5 bytes = 115 bytes. That doesn't leave much room for anything else. Well I should have looked at the maze more carefully, but the trick is here:

LF1EF: LDA $8C,X
ORA #$AA ; 10101010 This explains how the maze is so big.
STA $F4 ; He's only using every other bit for each line of PF data.
STA PF1
.
.
[code passes...]
.
.
LDA $8C,X
AND #$AA ; 10101010 the next line
STA $F4
STA PF1



It makes sense when you look the screen shot: http://www.atariage.com/screenshot_page.html?SoftwareLabelID=294

-Paul

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