All the autodetection rules should be enhanced in a way
so that they don't only check, if a decent feature is
present, but if it is valid and/or working, too.
Concretely I want d64copy to check, if an autodetected
parallel cable is working 100%, before it is used. I
the autodetection finds that the cable has got some
failure, it should print otu a warnign and fall back to
the next capable transer mechanism.
At my test environment it happened that there was a
1541 disk drive with a somewhat blown VIA chip the
parallel cable was connected to. I didn't recognize
this and thought d64copy got a software problem (bug).
Then I checked with MNib and this one told me a "Code
verify: FAILED" which brought me to the idea that the
parallel cable is not working.
In case of the parallel cable it should be enough for
the validness detection, if the four values:
55/AA/00/FF are transmitted, or 5A/0F/A5/F0, or ...