MAMEWorld Forums - EmuChat - Re: skyarmy and rom FIXED BITS curiosity

>> Looking over thread, definitely some good examples. I had thought there was some
>> protocol to have any roms with fixed/adjusted bits to be given some // fixed bits
>> comment description.

>"fixed bits" in terms of romcmp means that every byte in the file has that bit set (or
>clear?) i.e. it's fixed at a certain value. It doesn't mean it has been "fixed". It
>usually indicates that it was badly dumped, but in the case of the outrun sample rom then
>it was badly manufactured.

>People might pull that over into the mame source to remind themselves or others that the
>dump is bad/questionable/nothing to worry about.

>A single bit caused by bitrot won't ever be detected and once it's been (let's say)
>"repaired" then a comment is largely irrelevant. I would have thought it would be marked
>as "ROM NEEDS REDUMP" as there is no guarantee that only one bit was wrong.

Solid information there as well as AJR's and Haze's. I can see this being useful in MAME QA roms section even though it gets into nitty gritty details that most end users wouldn't be dealing with.

I was planning on asking a question about this long ago when Midway Road Runner was going through this same issue, but this was around time that either CPS-3 protection (2007) had finally been figured out or maybe it was when some laser disc games were starting to be emulated and the forums (2009), including old MAME.net back then, had been jumping around with excitement at the time. I decided to wait and ask the question later. I didn't expect the question to be another ten years later, but Skyarmy looked like the right moment to ask the question. ;-)