Reading DOS/Windows Backup tapes

Wow , this is the first really big programming project I've thought about working on  since college.  I was happy there for a while, just sitting back and not doing anything really challenging.  Then, in my usual way, I decided to see if there was anything I could do with the big stack of QIC-2120 and TR-1 tapes I've got sitting around with lots of really old data on them (going back to 1994).  I was recently inspired by a cheap purchase at the University of Michigan's Property Disposition (the place they surplus stuff) and found an IDE TR-4 drive.  I'd also gotten a TR-5 through eBay but found that the tape format was significantly different that it wouldn't read the tapes I had at all.  I've found the TR-4 to be similar (though it does actually read something).  So, I'm left with my Iomega TR-1 drive (noisy as hell) and I also obtained a pretty nice HP/Colorado T1000 some time ago.  These are both floppy tapes and are thus pretty slow. 

In any case, my investigations have led me to a pretty sweet site by Will Kranz that has a project that will read QIC113 in the version Microsoft came up with for their Windows 95/98 Backup application and MTF tape files.  After some monkeying around I found that unfortunately these wouldn't read files from tapes created using dd.  After some digging around and also looking at the mtf project, created by Alan Stewart,  I found that there doesn't seem to be anything like what I want to do.  mtf wants to read files directly from SCSI tapes and seems to have difficulty reading from ftape drives and Will's project focuses on reading just the files (as you would create them on a disk for instance).  Will also sent me a program that should just read the backups from the tape.  I think I want to try to avoid that at the moment because I need to back another step and just get data out of the tape format that it arrives in.  Again, here Will's site has been invaluable, pointing me to the QIC standards page which has mostly what I'm looking for.  Once I'm able to create a straight backup file from the dd'd image, one of these other projects (or even the original programs) ought to be able to read the file straight.  I will probably create some test files to test this out, since I just put together a DOS/Win95 machine with the Iomega attached.  The HP/Colorado T1000 is attached to my primary file server and is much more reliable and quiet than the Iomega POS. 

Well, I might as well publish my notes so far.  These two documents reflect the information I've gleaned so far by just reading the QIC standards documentation and using hexdump and hexedit.  I would welcome any comments on them.

Thanks, Will, for your help so far.

Last night I made an interesting discovery.  The only difference between the Microsoft Backup tape images (bit-copied from a MS Backup tape) and the MS Backup disk files (.qic) is the VTBL header information.  I could easily see converting tape images to disk files by manufacturing VTBL info.  I just don't think I have that many MS Backup tapes.

I am having a bit more difficulty with the Central Point backup  information.  There seems to be less correlation between the tape images and the disk files. I am also having difficulty getting CP Backup to recognize my tape drive.  It keeps giving me a divide by zero error.  I don't know if this is due to the relatively modern hardware I'm attempting to use or if there is enough difference between the Iomega Ditto 800 (TR-1) and the Iomega Tape 250 drives to cause CP Backup to choke and die.   I may just have to come up with a  Pegboard 486 and see if I can't get something to work.