4 Mar
2006
4 Mar
'06
8:29 a.m.
At 8:48 AM +0100 3/4/06, Johnny Billquist wrote:
I know I had issues with a drive that worked just fine in my
AlphaStation 200 4/233.
And if you have to you can restore from CD-R. A couple of us have
theorized that it should work just fine to 'dd' back to the same
model drive (I can't see any reason this wouldn't work), but I don't
believe anyone has attempted this with a SCSI drive (I've done it
with RL01's and RL02's).
Zane
--
--
| Zane H. Healy | UNIX Systems Administrator |
| healyzh at aracnet.com (primary) | OpenVMS Enthusiast |
| MONK::HEALYZH (DECnet) | Classic Computer Collector |
+----------------------------------+----------------------------+
| Empire of the Petal Throne and Traveller Role Playing, |
| PDP-10 Emulation and Zane's Computer Museum. |
| http://www.aracnet.com/~healyzh/ |
"Zane H. Healy" <healyzh at
aracnet.com> wrote:
I very much doubt it. Writing to a CD-R is not done the same way as
writing to a disk. And MSCP-SCSI controllers only do writes as to a
disk.
CDs need to have lead-ins, lead-outs and whatnots in between.
(Underruns, anyone?)
When using CDRECORD on OpenVMS aren't you writing to a MSCP-SCSI
device? Granted it's a lot more modern, and the SCSI controllers are
probably more advanced.
I
don't really know anything about MSCP or the SCSI command set that CD
writers use - but could a CD-R(W) drive be used as a backup device?
I know it's bad style to do backups on CD-R, but bear with me :)
I don't see why not, but you'll have to write the software to control it. You're also
likely to find that it's very picky about what it will work
with. At least with my Viking QDT and UDT controllers I *think* 512-byte
blocks are a requirement, and I know they won't work with all 512-byte block
CD-ROM drives.
My CMD controllers have been happy with every CD drive I've tossed
at them, but I admit it hasn't been that many different models, so I
might have been just lucky. An easier
sollution is to have the SCSI HD's in removable trays, and Have a
modern Unix box with the same type SCSI tray. Plug the PDP-11 disk into the
Unix box, and use 'dd' to image the disk. The resulting image can even be
used under SIMH.
That would definitely be easier. If you wanted backups, you could
then burn that image to a CD on the Unix box.