Asteroids source/disassembly?

[Feralstorm]

I haven't done a lot of searching, but I have done some, and come up dry.

 

There's a lot of hacks of Asteroids out there - has anyone got source code/disassemblies for 2600 Asteroids? (preferably with comments, but I take what I can get)

[Thomas Jentzsch]

I have something at home. Will post tonight.

[Cybergoth]

Hi there!

 

I have something at home. Will post tonight.

 

Yay, finally!

 

Greetings,

Manuel

[Thomas Jentzsch]

Yay, finally!

"Something", not complete!

[Thomas Jentzsch]

I hope it helps.

Asteroids.zip

[Feralstorm]

Thankyew.

 

I barely qualify as a hacker, but I've done a few things, and the variations of Asteroids in the FB2 started me thinking in "How I woulda dunnit" terms.

 

I don't have the programming skills (or the patience to learn) to do much beyond graphic hacks tho'

[Feralstorm]

Thanks again for the disassembly. I'm in the middle of a hack which will get lost in the wealth of Asteroids hacks out there, along with a test or two of graphic experiments. I'm just a bit-hacker, but there's a lot one can do in bit hacking when one has a roadmap.

 

Which leads me to a follow-up question for anyone willing to listen. Is there a way (with bit-hacking) to disable the difficulty switch check? My goal is to set the UFOs as on regardless of the switch position.

 

Thanx in advance

[Thomas Jentzsch]

Which leads me to a follow-up question for anyone willing to listen. Is there a way (with bit-hacking) to disable the difficulty switch check? My goal is to set the UFOs as on regardless of the switch position.

Search for SWCHB (probably BIT SWCHB) and where the two highest bits are checked (probably by bpl/bmi and bvc/bvs).

[Feralstorm]

Thanks again for the aid. I managed to do what I was shooting for mostly by trial and error, since I was bit-hacking as opposed to assembly-hacking. Sorta like turning on and off lamps in your home by pounding the circuit breaker with a hammer. No apparent side-effects so far, so I'm hopeful.

 

I also stared over, using Sadistroids as a baseline this time (since it already had a few things I wanted already in place.) Hope you don't mind... eheh.

 

Getting close to done either way - watch this space.

[Thomas Jentzsch]

I also stared over, using Sadistroids as a baseline this time (since it already had a few things I wanted already in place.) Hope you don't mind... eheh.

No problem. After all, it's only a hack.

[Feralstorm]

Okee-doke.

 

I'm beta-testing/playtesting and tweaking, mostly so the "slow" game doesn't totally kick my ass.

[Nukey Shay]

Okee-doke.

 

I'm beta-testing/playtesting and tweaking, mostly so the "slow" game doesn't totally kick my ass.

939741[/snapback]

 

In cases of checking just to make sure that the game mechanics work as expected, I usually add in cheat options to the assembly file (most game cheats are easily added by looking though the listing for collision register checks). For example:

 

      BIT CXPPMM;check player/player collisions
     BPL LXXXX;branch if no collision

 

...could be changed to be:

  IF CHEAT
     JMP LXXXX;always skip to the "no collsions" address
     NOP;extra byte
 ELSE
     BIT CXPPMM;check player/player collisions
     BPL LXXXX;branch if no collision
 ENDIF

 

Then at the top of the assembly, you can set CHEAT to be 0 or 1 before you assemble the binary.

 

'Course, not all games use collision registers