Ruud_at_baltissen.org
Date: 2008-01-01 12:33:38
Hallo Jim,
> As stated before, I'd prefer to see the drive contain a std IDE boot
> sector (with partition info), and put this stuff at the sector noted by
> the partition info.
Ah, then I understood things wrong. IMHO no problem at all. This will
simply meean that everything just shifts one sector. Having no idea
(anymore) how the boot sector looks like, for the moment I assume that the
C= partition always starts at the second sector. If I have learned how to
interprete the boot sector, I can always move things up.
Question: is one able to boot from an harddisk if the first partition is
non-DOS (or whatever other OS)? Favouring the 8-bits system for the moment,
an 8-bits card, like my proto type, cannot read a sector written by a 16-
bits system and thus cannot determine where its partition starts! Using
your card that is no problem, of course.
> On the disk, I think that is fine. However, I would still leave a spot
> on the DIRectory block for the ID and DOS-type (2A), in case someone
> wants to modify them.
At this moment everything is still standard 1541. The disk ID is, beside
the write protection detection, just there to see if the disk has changed.
As an harddisk cannot be changed and so there is no really need for an ID,
I decided to ommit the routines and memory related with it. But the ID can
still be changed if needed (just tested it).
To be honest I had no place reserved for an ID in my LBA system but no
problem at all to reserve some bytes for it in the first sector (of the
partition).
> I'm not sure I understand this. You mean for "locked" files (>PRG) and all?
No, a switch that more or less disables one to write to the harddisk, it
will be only a software protection. In the 1541 the WP detection also
blocks the writing electronics electronically. This is not possible with
the HD unless we do something with the interface. Have a look at $F57A of
the original 1541, then you see what I mean with the software protection.
@allemaal:
I ran in a weird problem. At this moment I haven't any idea anymore if I
already mentioned it, so if I did, sorry.
Formatting a disk with ID immediately after a reset is no problem. Doing it
a second time messes things up and the format ends with the message
25, WRITE ERROR,18,00
and the directory just shows
0 "
Doing it a third time I still get the error but I get a decent directory
(which doesn't tell how the rest of the BAM looks like). Another problem is
that I just noticed it (who ever formats a disk twice in a row ???). But
the error is already present in version IDE1 :(
One good thing: a format without ID after such an errorous format clears
the air again.
What puzzles me is that, AFAIK, in version 1 I just 'messed' with the I/O,
not with variables etc.
If anyone is interested to have a look at it:
http://www.baltissen.org/files/idejd1.asm
http://www.baltissen.org/files/ide1.asm
Many thanks in advance!
--
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/ / |_/ Groetjes, Ruud
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\___| http://Ruud.C64.org
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