19 Jun
2010
19 Jun
'10
2:48 p.m.
On 19 Jun 2010, at 19:19, Fred Cisin wrote:
I know what you mean. That is another thing we've worked hard to determine. If we want
to preserve games as they were originally produced, it is very important to us that we can
be sure it is the original data. So, before we started trying to preserve anything, we
worked out how to see the difference between something written by a commercial mastering
machine, and something written by a home system (or indeed between two systems). That way,
if it is a copy, or there is virus or other modifications, we know we need to look for
another copy. Even hiscores and save games mean we'll look for another copy. Of
course, this is all completely games and commercial software specific concerns.
It was certainly a good one to start on ;-)
Ummmm. People on THIS list tend to be rather obsessive in our hobbies.
"a few hours a week"??? That's barely a casual interest, nuch less a
serious HOBBY!
Well, I'm in good company then. :) Our main technical guy, who is actually behind all
of our tech once admitted to me that he usually works 8 or more hours a day on this. I
wondered how that was possible, and then I remembered that he simply doesn't sleep.
Kieron
We can certainly agree to call the IBM/WD MFM (barring
weirdnesses) to be
a category of format. For your purposes, duplicating/storing/analyzing
the physical format data, all that would be relevant among those would be
"density", number of cylinders, number of sides, number of sectors per
track, and bytes per sector. Typical weirdnesses would include such
things as unconventional sector headers (invalid cylinder, head, sector
numbering), different physical formats on different tracks, abnormal gap
sizes and content, etc.
You also get to deal with all of the non- IBM/WD style sectors.
We spent a long time coming up with a way of handling that sort of thing automatically. It
was a difficult problem to solve, but I'm fairly unashamed to say that now we have, we
think it's very neat. Too bad it's useless outside our very niche area. :)
producing disk
images that can be verified by any integrity information
we can find (and we don't mark them as done until we do). Given our
Hmmmm. If you needed a third party objective test, . . .
Make two copies. Give the original and the two copies to a hacker who
would attempt to identify which one of the three disks is the original. We do indeed
do analysis of inter-sector and inter-track gaps, because
some types of copy protection use those areas.
The Amiga certainly is capable of significantly more weirdnesses of that
than we need to deal with! Can it be done as anything OTHER than a hobby
project?
There certainly doesn't seem to be enough economic incentive to put in
that much work. I kept at it for years after it no longer paid the bills.
I meant
it isn't a hobby in the sense that you can do for a few hours a
week at your leisure. I think it would have to be termed more of an
obsession, or unpaid work, than a hobby. :)