Re: [stella] Starmaster disassembled

Subject: Re: [stella] Starmaster disassembled
From: "Thomas Jentzsch" <tjentzsch@xxxxxx>
Date: Fri, 3 Aug 2001 10:08:36 +0200
Andrew wrote:
> I've said it before, I'll say it again, and I'll probably KEEP saying it.
> Use the overlay system I used in Qb to manage your variable reuse.  Its easy
> to use, doesn't require you to remember what's used where, and works
> brilliantly!  The overlay system took variables from a severe problem in Qb
> to one of the lesser things I had to worry about.

I basically did the same, the main difference is, that I don't have a single overlay block, but several (mini) blocks of renamed variables. After having a closer look at your code, I must agree: your solution looks much more elegant!

Unfortunately, I was that short of RAM, that I couldn't use a single block.
I.E. I had to reuse the hi-pointers of the score data AFTER I had calculated the lo-pointers. So I could only use only every 2nd RAM space of that 12 bytes block. And that's easier done with simple variable renaming. 

I also had to share variables bitwise, which means the first bits are accessed under a different name than the last bits, because their meaning is totally different. That of course, required a bit more comments than I'm normally used to do ;-) 

So, now you know, why I sometimes got confused :)

But using a single overlay area (as long as possible) is CLEARLY the best way to start!

Have fun!
Thomas Jentzsch         | *** Every bit is sacred ! ***
tjentzsch at web dot de |

______________________________________________________________________________ - Urlaub ist schön!
Hier geht's zum Traumstrand:

Archives (includes files) at
Unsub & more at

Current Thread