Questions about "scheme types"

[martingzzz]

1) The downloads table has a column schemetype_id, which can be NULL. There are also schemetypes with text "None" and "Undetermined". I assume "None" means explicit there is no scheme, which makes sense, but "Undetermined" seems to mean the same as NULL to me. I suspect either "Undetermined" doesn't need to exist, or schemetype_id on the downloads table should not be nullable.

Does this seem correct, or have I misunderstood something (again!) ?

2) Some of the scheme types are the same as their identifiers and seem suspicious compared to the rest. Examples are ED, H, ZV. Is there an explanation for this?

[lfaria]

1) The downloads table has a column schemetype_id, which can be NULL. There are also schemetypes with text "None" and "Undetermined". I assume "None" means explicit there is no scheme, which makes sense, but "Undetermined" seems to mean the same as NULL to me. I suspect either "Undetermined" doesn't need to exist, or schemetype_id on the downloads table should not be nullable.

Does this seem correct, or have I misunderstood something (again!) ?

I understand that "Undetermined" means there IS a scheme involved, but either:
- It was not analyzed and thus not categorized yet
- It was analyzed and doesn't fit any of the "known" / "defined" ones
But clearly it's not "None".

[martingzzz]

Thanks for the reply.

If "undetermined" means there is some protection involved then the data looks suspicious to me. Around 60% (7369 out of 12329) of the "undetermined" downloads are tap files, meaning they have standard loaders. It's possible they have some other (non-tape based) protection schemes that have been analzyed and not categorized, but this seems like a very high number if that's the case.

[SkoolKid]

Around 60% (7369 out of 12329) of the "undetermined" downloads are tap files, meaning they have standard loaders.

Not necessarily. Some games in TAP files have custom loaders that happen to use the standard ROM timings. Removal Deluxe is a good example.