Asteroid Storm

[wesmond]

Hi,

I checked Virgin Books, ASTEROID STORM - for which you have an unverified BAS version. The listing you have is very similar, but not identical - and in this case, yours works, but the original listing, as far as I can tell, crashes and locks up during initialisation (before the USR(start) is called), because the initialisation code reads in data into memory that overwrites the last line of program code, corrupting the data statements at the end before it gets to reading them.

The version you have reduces the memory usage sufficiently with a few changes - POKE 106,79 instead of 106,59, removal of almost all the REM statements, and using a variable PA=256, and replacing 256 with PA throughout the code, replacing chr$(125) with the escaped symbol... it probably reduces the memory size just enough bytes. And then, strangely, lines 13010,13020 add a few more sound statements... so I don't really understand what's going on.

ANYWAY, attached is a file with the listing exactly as printed, even though I couldn't make it work! Your version has exactly the same "meaning" as the original book, except for lines 13010-13020, where the sound effect uses extra channels in your version.

Cheers,
Wes

[wesmond]

AHA! I've just found a little message in the Special Programming Notes, p8 of the book that says, ' "Asteroid Storm" for example will not run with a DOS that takes up more memory than Atari's DOS 2.0'. My ATR was DOS 2.5. NEVER-THE-LESS, your version runs happily in DOS 2.5. The book recommends typing POKE 9,0, then RESET and RUN - which didn't make any difference on mine!

I'll see if I can find a DOS 2.0 ATR to test it on...

W.

[wesmond]

Nope, couldn't get the original to work on a DOS 2.0 disk either!
W.