From: Nicholas Zymaris (nickz@eskimo.com)
   Subject: Help with PRO 380 disk recovery
   Newsgroups: vmsnet.pdp-11, alt.sys.pdp11, comp.sys.dec.micro
   
   Date: 2001-03-08 12:52:13 PST
   
<<
I have a PRO380/RD52 which won't boot. I'm convinced that it's only
the home block that's corrupt. Won't go into the detail about how I
got to that conclusion, but I'm 99.9% sure.
Usual story, customer broke his backup disk as well on the faulty
controller which caused the problem in the first place, and doesn't
have any off line backups.
So, I need to try to recover the data files, or make the disk bootable
again.
>>

I wrote a disk recovery utility for the Pro which boots P/OS
off of an RX-50 floppy and then allows you to run a simple
sector editor (QIOLOG) as well as PIP, VFY, etc.  It also
mounts the hard disk as DW1: if needed.  This P/OS runs
entirely from the diskette, so it will work even if your hard
disk is not bootable (and will allow a bootblock or homeblock,
etc. to be modified so you don't have to reformat the disk).
I wrote it for exactly the kind of problem you are
experiencing.

You will need to copy the disk image to a floppy (e.g. with
PUTR in foreign mode, or Strobe's FDISKIMG or any similar
utility.  It is a standard RX50 floppy.  It will be easier if
you then replace the QIOLOG executable on the emergency disk
with the newest one which is better at defaulting unspecified
parameters and providing the option to calculate and write file
header or home block checksums.  However, the existing floppy
disk set is ready-to-use and also works if you don't want to
replace QIOLOG.

The bootable disks which are ready to use are at this URL:

http://nickzz.tripod.com/dec/emergency.exe
[1-May-2001 moved to: http://www.eskimo.com/~nickz/dec/emergency.exe]

It is a self-extracting ZIP containing the boot disk and the
application disk, both RX-50 images, ready-to-use on a Pro.
If you have a normal PC high-density 5 1/4" floppy drive, or a
Rainbow RX-50 drive, you can generate a floppy readable by the
Pro by using John Wilson's PUTR:

putr
mount du: a: /rx50 /foreign
copy/dev disk.img du:

Or use Strobe Data's FDISKIMG:
fdiskimg a:

(make sure it specifies 800 blocks and change as needed).
(Use B: instead of A: if that is where you hooked up the
RX-50).

You can also Kermit the disk images to a Pro, but that won't
work of course if your Pro is not working; the disk image can
then be copied to a floppy using QIO's with vbn2lbn.tsk which
is on my web site.

The updated QIOLOG.TSK (31-Jan-1999) executable is at:

http://www.eskimo.com/~nickz/rsx11m/qiolog46.zip

You can copy QIOLOG.TSK to a floppy using Strobe Data's SFX
V1.28 which can mount a container file or a real RX-50, much as
PUTR does for RT-11 disks.  However, SFX will not preserve its
contiguity so you'll then need to use PIP to COPY/CONTIGUOUS
it, e.g.

(Boot the first floppy to get P/OS Diskette System into memory)
(Insert the second floppy and run PIP from the menu)
(for this example, the new QIOLOG was copied to dz2:[0,0] using
SFX, while the original disk with QIOLOG (old) on it is in
DZ1:.  You could also just delete the old QIOLOG with SFX and
copy the new one to the same location, without using an extra
floppy, but you stilll have to make it contiguous to run it.)

PIP>dz1:[zzqiolog]qiolog.tsk;0/de
PIP>dz1:[zzqiolog]/co/cd=dz2:[0,0]qiolog.tsk
PIP>^Z

(Now select QIOLOG from the menu, and Read Logical Block 0,1.
Make any desired changes by selecting Edit/Zero; when you are
done, select option 3 (stop editing) and then Calculate Home
Block Checksums.  Then Write Block, Previous Block, Yes.  You
can then either reboot from the Select New Device menu or use
Micro-ODT or turn the system off and on, and boot your hard
disk if the home block was fixed properly.)

--
Nick Zymaris
nickz@eskimo.com                               IC XC + NI KA