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Re: Hardware musings
Michael J. Mahon wrote:
It is not possible to know that a disk is "normal" except by doing
"sufficient" testing, which is beyond an algorithmic procedure.
The normal flag is for regular disks like data disks or kracked stuff or
whatever.
It is always possible that a program tests for a condition which is
a "don't care" in a normal disk, but which is fully specified in the
"original" disk--in fact, this is a fairly sophisticated scheme of
copy-protection. ;-)
Yes but we copy the entire bit stream regardless.
Such a track could appear to have virtually any length--in fact, if
the nibbles were written in isolation with the rest of the track
written as 0's, then the track would appear to be *almost* completely
random--it would be easy to miss the short "magic" pattern in the
sea of random nibbles.
Not if one evaluated the boot procedure. Besides, the EDD card would
see the pattern as well as Copy II+ hires disk scan...
What exactly is the purpose of all the checksums?
Someone suggested that the current files were subject to corruption
during transmission or the occasional twiddled bit. I agree and think
you should consider checksumming each track so you know where the issue is.
I also noted that unless quarter tracking on a spiral, no disk will
have tracks closer than .75 tracks away. or a total of 48 tracks
stored assuming you used quarter tracking between 35 and 40.
And again, the problem is knowing when data is relevant and when it
isn't.
But you can tell a spiral disk from the sound... It is SOOO obvious.
Maybe I sholdn't worry too much about file size in this day and age, but
a 6x or so expansion over a normal image does seem a bit severe,
No worries unless it is a spiral disk. Those images promise to be up to
512k in size! (39x4 +1) x 6.25k
But assuming the disk has ever been deprotected or even monitored while
booting, the protection routine will be known and where it is at. Most
protection schemes rely on data inserted between normal sectors that
does not get read by normal copy programs. The bit steam format catches
all of that.
Thankx,
Ed