Imaging SCSI hard disks

Jerome H. Fine jhfinexgs2 at compsys.to
Wed Sep 1 22:00:34 CDT 2004


>Doc Shipley wrote:

>    I dunno about other OS disks.  The little I know about RT-11's
> filesystem implies that most any old disk should work.

Jerome Fine replies:

Normally, I find it a bit inconvenient to use a hard disk
to copy stuff back and forth from RT-11 running under
E11 on a Pentium and a real DEC  PDP-11.  If someone
is trying to do this and is having problems, I will suggest
how I solved the problem.

For myself, while I have used a hard SCSI disk drive
to be sure it is possible, I find the use of magneto optical
media a bit more convenient.  Since the media is removable,
the PC does not complain when I boot that the media is
not in the drive.  Then under E11, I am able to:
MOUNT  DU0:  SCSI0:

Of course, on a real DEC  PDP-11, I must use a SCSI
host adapter.  I have a CQD 220/TM which does the
job along with an Adaptec AHA2940-AU on the PC.
A Sony SMO S-501 drive on each system completes
the needed hardware to allow me to transfer 300 MBytes
back an forth.  I also use the MO media as a backup for
the 600 MByte ESDI hard drives (Hitachi DK515-78)
on the real DEC  PDP-11.  Since each ESDI hard drive
has 20 RT-11 partitions, I use both sides of each MO
media PLUS 4 RT-11 partitions from another media.
It required very careful co-ordination, but is MUCH
better than a tape since any small changes can be
made on the MO media to keep the backup up to date.

Sincerely yours,

Jerome Fine
--
If you attempted to send a reply and the original e-mail
address has been discontinued due a high volume of junk
e-mail, then the semi-permanent e-mail address can be
obtained by replacing the four characters preceding the
'at' with the four digits of the current year.




More information about the cctalk mailing list