I have had multiple interesting and useful answers. Thanks everyone. I checked on VMS 7.3 and there is no COPY/IMAGE there. BACKUP/IMAGE had been my first thought, but it won't accept a tape as the source of the image data unfortunately.
I have a TZ30, so I will try that on Ultrix. I will also try a more recent Unix (Debian probably) on an Alpha and see if that can read from a later drive. May last resort is to write my own VMS QIO-level program to read raw blocks myself. Regards Rob > -----Original Message----- > From: cctalk [mailto:[email protected]] On Behalf Of Robert > DiRosario via cctalk > Sent: 16 June 2017 15:28 > To: [email protected] > Subject: Re: dd-equivalent for VMS > > You could remove the disk from your Ultrix box, install another diskand > install > NetBSD. The Pmax version works on the DEC MIPS > boxes:http://wiki.netbsd.org/ports/pmax/. You could also do that on your > DECAlpha. > The TK50Z should be a SCSI drive, you could also just move the drive to > another > UNIX/Linux/BSD box > > It's been a while since I played with any of my vintage computers that have a > TK50 drive. Could it be that the SCSI controller / bus in the Ultrix box > isn't fast > enough to handle the tape drive at "full speed"? You could try putting the > drive > on a modern computer with a modern SCSI controller with nothing else on that > SCSI bus. > > Ten plus years ago I was working on a satellite ground system and we needed > to record the real time down link so we could use it to test the system. The > data was written to a SCSI DLT drive. The speeds listed for most tape drives > are > peak speeds, and it was very hard to get a sustained data rate that was close > to > the peak data rate listed by drive manufacturers. > > Robert > > -------------------------------------------------------- > Is there a dd equivalent for VMS? > > Background: > > I am trying to recover some TK50 tapes that were written on Ultrix. > > I have a MIPS machine with Ultrix 4.5 on it and a TK50Z drive. I have been > able > to read some tapes but they all seem to get an I/O error after a while of > reading. I think this could be due to the accumulation of oxide on the heads. > Despite cleaning the heads after every tape (by disassembly and cleaning with > isopropyl on a cotton bud). I think the oxide is accumulating more than > necessary because of the poor streaming abilities on the TK50 drive (too much > back and forth over the same section of tape). > > > > I do have more modern drives (TK70, TZ85, TZ87 etc), but Ultrix does not seem > to recognise them. So I was hoping to use one of my VAX or Alpha machines > with VMS and a better tape drive to recover the raw data. Ideally I would like > to make a SIMH virtual tape clone of the real tape. > > Any other alternative suggestions very welcome.
