Disabling sprite collisions

[Luc]

How can I disable sprite collisions in Atari 2600 games? I remember the Commodore 64 had certain addresses that kept track of the sprite/sprite and sprite/character collisions, but how does the Atari do it? I've been looking for some info on the net, but could not really find anything helpful. I'd appreciate it if someone could point me in the right direction.

 

Thank you.

[+batari]

How can I disable sprite collisions in Atari 2600 games? I remember the Commodore 64 had certain addresses that kept track of the sprite/sprite and sprite/character collisions, but how does the Atari do it? I've been looking for some info on the net, but could not really find anything helpful. I'd appreciate it if someone could point me in the right direction.

 

Thank you.

Same deal, as there are 8 addresses that hold sprite collisions ($00-$07) but sometimes the games use mirrors of these addresses (usually $30-$37.)

 

If you want to disable all collisions in a hack, a foolproof way is to insert a STA CXCLR at the end of the kernel. This requires two bytes, so it might not be feasible.

 

To change individual collisions to a binary in situ is usually possible but a little harder. In my experience, most games access them with A5 xx where xx is one of the addresses above. To disable, change the two bytes to A9 00.

 

However, some games might access them using 24 xx, which is harder still, but can be worked around. Change to 24 0F and (I think) this will work, as I've read that the TIA will output zeros on an unrecognized address. I haven't tested this, so be warned.