[Coco] Backup of HDB-DOS drives
gheskett at wdtv.com
Tue Jan 17 06:14:02 EST 2012
On Tuesday, January 17, 2012 05:56:22 AM Bruce W. Calkins did opine:
> ----- Original Message -----
> From: "Jim Hickle"
> I'd like to backup HDB-DOS drives from one device to another. I have
> SCSI drives. Perhaps I could use BACKUP in a loop but don't know if
> it's possible for HDB-DOS to address two different devices.
> I'm thinking of using NITROS9 with a device descriptor set up for source
> and destination HDB-DOS, open each as a raw device, and copying 256 *
> 35 * 18 bytes. Do we have a program like Linux's 'dd' ?
> For my RGB-DOS system I wrote a FOR : set drives : BACKUP :switch drives
> : BACKUP : NEXT loop from one hard drive to my ram drive and back to
> the other hard drive. I never did find any was to copy directly from
> one hard drive to the other.
> Bruce W.
I wrote a dd.b09 3 or 4 years ago, but I haven't inflicted it on anyone
else as it is very very slow for some reason even with verify turned off on
the target disk. Its a bit tricky because after the first sector, lsn0 has
been written, os9 throws up a disc change error, so you have to write that
sector, close the path, and re-open it before os9 will allow the image to
continue to be written. I'm sure there is a magic twanger that will write
at a decent speed, usually in odd values of interleave from the default of
3, but that then slows the subsequent read performance too.
On the face of it, a simple "copy #56k /d0@ /d1@" should work, but the disk
change error kills it quickly.
For installing a new nitros9 release, I have been known to trick a second
HD descriptor into thinking the .dsk image, once sz'd to the drive, was a
separate floppy, and did the install without ever writing a floppy with
that .dsk image. But to make that work I believe you need to be using the
Superdriver disk system which can do 'partition' offsets.
Lots of creative ways to skin that cat.
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