saving is boot0. If it is, use its version number so that we can grab
all of boot0 (1024 bytes with version 1.1 for example) when we save it
to a file via the 'f' option. Otherwise, we just save the first sector.
- Cleanup this code a bit by splitting some functionality out into separate
functions.
Suggested by: Patrick Bihan-Faou <patrick@mindstep.com> (1)
- Allow for boot0 to be more than one sector long. However, ensure that it
its length is a multiple of the sector length.
- Change the signatures used to determine a valid boot0 as some of the
signature code changed.
- Use the old signature to detect version 1.0 of boot0, otherwise read the
version number from boot0 itself.
(with care) in those instances where boot0 is not passed the
correct drive number by the PC BIOS. (The symptoms are a
"F5 Drive 0" line, even though the current drive is drive 0.)
