Lasermania NTSC fix.

[_The Doctor__]

okay so where is the ok it's working now version? I'm not sure which is which now...

[nobody]

8 hours ago, matosimi said:

It's ok now.

Could you get the info what did the trick? Maybe $240 ?

They create a checksum from memory at $501-$5ff (original boot loader) and compare the result with $240. The address pointers are build with indirect addressing and bit operations so there was no direct access to the relevant meory (have a look at $a217) ...

 

@_The Doctor__

http://www.mushca.com/f/atari/index.php?idx=L#138|LASEANIA

 

[matosimi]

1 hour ago, nobody said:

They create a checksum from memory at $501-$5ff (original boot loader) and compare the result with $240. The address pointers are build with indirect addressing and bit operations so there was no direct access to the relevant meory (have a look at $a217) ...

 

@_The Doctor__

http://www.mushca.com/f/atari/index.php?idx=L#138|LASEANIA

 

Yes i know, that's why was I asking ... i have checked too many executables these days so I had no energy to check once more since I already found the solution.

...however I was curious if the check was completely removed or just inserted required value compared with the checksum.

[nobody]

7 minutes ago, matosimi said:

Yes i know, that's why was I asking ... i have checked too many executables these days so I had no energy to check once more since I already found the solution.

...however I was curious if the check was completely removed or just inserted required value compared with the checksum.

I found 3 locations where someting was checked:

$9847..., $a176..., $a217... - all checks are disabled now...