[Coco] Backup of HDB-DOS drives

[gene heskett]

On Tuesday, January 17, 2012 10:17:06 AM Robert Gault did opine:

> Jim Hickle wrote:
> > 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'
> > ?
> 
>   The Ken-Ton scsi interface used with the RGBDOS system could only
> address one scsi device at a time. I'd be surprised if the Cloud-9
> interface is significantly different in this regard. As a result of the
> hardware limitation, RGBDOS could not copy or backup directly from one
> scsi drive to another.
> 
>   Bruce's suggestion of using an intermediate RAM drive (if you have
> 512K RAM) is a good one and about the only thing that will work with
> RGBDOS (or I suspect HDBDOS.)
>   As Gene indicated, using OS-9 to backup HDBDOS drives needs to be done
> carefully to avoid errors generated by changing LSN0. Whether you run
> into this type of error will depend on the driver you use to access the
> HDBDOS drives. Written correctly, the driver should only see LSN0 of
> the OS-9 partition for the two scsi drives. The HDBDOS drives will be
> accessed using a sector offset value so there would not be a change to
> the LSN0 values. With this scheme, you would need a custom track copy
> program, Backup would not work.

Not being aware of that single drive limit, the instance where I did 
the latest nitros9 install by using the drive descriptors partition 
offsets to address the .dsk image directly, I forgot to note than 
when I sent the .dsk to the coco, the shell that received it was chd'd to 
/S1, which is a second scsi drive, identical to /dd but formatted 100% 
to os9, so its "cluster size" is 16 since its a full binary gigabyte 
drive.  Then I did a dir -e to find the lsn0 of the file and adjusted 
the descriptors wpc=00 ofs=0000 values so they pointed at the LSN0 of 
the .dsk file.  At that point, /s1 was effectively an 80 track floppy,
and I did a dsave install of the latest build from my own repo.

I have no clue if I could have dmoded /s1 to point at that file 
successfully or not had that .dsk been written to /dd. scsi drives 
are pretty smart, and unless there is an os9 reason, there shouldn't 
be any huge showstopper to doing exactly that if you only have one 
physical drive.

IDE drives OTOH, may not be that smart.  I have NO experience with them 
and how they behave on a coco system.

Change of subject here.

Because the threat to our group from SOPA and PIPA is very real, 
outlawing all of our efforts to provide a distributed archive of 
everything coco related, there is a move afoot on several other lists 
to effectively shut down the net, at least the html based stuffs on it, 
for 24 hours starting at midnight tonight.  I will join in this effort 
to draw attention to this very wrong legislation myself by replacing 
my root index.html with this one:
============
There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order
--Ed Howdershelt

This page is disabled in protest as it would be illegal under SOPA or PIPA.
Contact your congressional representatives and kill this worst legislation 
ever.  This is my soap and ballot box.
============
I have set it up as a cron job using this crontab:

[root at coyote gene]# crontab -l

59 23 17 01 * mv /var/www/html/gene/index.html /var/www/html/gene/was-index.html
00 00 18 01 * mv /var/www/html/gene/protest-index.html /var/www/html/gene/index.html
59 23 18 01 * mv /var/www/html/gene/index.html /var/www/html/gene/protest-index.html
00 00 19 01 * mv /var/www/html/gene/was-index.html /var/www/html/gene/index.html

Feel free to copy both.  This legislation must be stopped at all costs.  
And for those of us in the US, I highly recommend that any representative
who voted aye in this bill be unseated when he stands for re-election
this fall.  Bill passage or not, he is NOT representing we the people
and needs to be replaced with someone who does represent the people
instead of the MAFIAA donating to his re-election campaign.  I am sick
to death of having my congress critters sold to the highest bidder.

Cheers, Gene
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
My web page: <http://coyoteden.dyndns-free.com:85/gene>
Q:	What's tiny and yellow and very, very, dangerous?
A:	A canary with the super-user password.