Great Exploitations

What exactly is it looking for? I would think a good approachto flag a warning on any load of an address <128 other than a label taken from a list; as someone suggested, the list should be pre-initialized with TIA read regs, but you could have a comment-pseudo-op to add to it. Otherwise the E.T. Book Cart mistake would fall through. After all:

 LDA	somelabel

where somelabel==10 looks entirely reasonable from a parsing perspective. It's only if one realizes that somelabel ISN'T the name of one of the TIA regs (even though $0A is the address of INPT2).

What exactly is it looking for? I would think a good approachto flag a warning on any load of an address <128 other than a label taken from a list; as someone suggested, the list should be pre-initialized with TIA read regs, but you could have a comment-pseudo-op to add to it. Otherwise the E.T. Book Cart mistake would fall through. After all:

 LDA	somelabel

where somelabel==10 looks entirely reasonable from a parsing perspective. It's only if one realizes that somelabel ISN'T the name of one of the TIA regs (even though $0A is the address of INPT2).

It's very simple - it looks for a ZP read opcode with an operand <$80, and if the source isn't loading CX* or INPT* then it prints the offending line from the .lst. It does produce false positives sometimes but it has managed to find some errors.

 

I tried it with an old Crazy Balloon source that was known to have this issue and it found the bug. I also found a bunch of other source files I had on my hard drive, and it found a problem with an old source file for Bobby is Hungry (had "lda TIMER"). I don't know if the final game was fixed or not.

It's very simple - it looks for a ZP read opcode with an operand <$80, and if the source isn't loading CX* or INPT* then it prints the offending line from the .lst. It does produce false positives sometimes but it has managed to find some errors

 

Ah. I'd looked through the EXE for a list of TIA labels, but I guess you don't really need a list for those since they all start the same.