[TUHS] Determining what was on a tape back in the day

So, I came across this tape: http://bitsavers.trailing-edge.com/bits/DEC/pdp11/dectape/TU_DECtapes/unix6… I was curious what was on it,  so I read the description at: http://bitsavers.trailing-edge.com/bits/DEC/pdp11/dectape/TU_DECtapes.txt UNIX1 PURDUE UNIX TAPES UNIX2 UNIX4 UNIX6 HARBA1 HARVARD BASIC TAPE 1 HARBA2 HARVARD BASIC TAPE 2 MEGTEK MEGATEK UNIX DRIVER RAMTEK RAMTEK UNIX DRIVER Cool, sounds interesting, so I downloaded the unix6.dta file and fired up simh - after some fiddling, I figured out that I could get a boot prompt (is that actually from the tape?) if I: set cpu 11/40 set en tc att tc0 unix6.dta boot tc0 = At that point, I was stuck - the usual tmrk, htrk, and the logical corollary tcrk didn't do anything except return me to the boot prompt. I was thinking this was a sixth edition install tape of some sort, but if it is, I'm not able to figure it out. I thought I would load the tape into v7 and look at its content using tm or tp, but then I realized that I didn't have a device set up for TU56 and even if I did, I didn't know how to do a dir on a tape - yeah, I know, I will go read the manual(s) in chagrin. In the meantime, my question for y'all is similar to my other recent questions, and it goes like this: When you received an unmarked tape back in the day, how did you go about figuring out what was on it? What was your process (open the box, know by looking at it that it was an x rather than a y, load it into the tape reader and read some bytes off it and know that it was a z, use unix to read the tape using tm, tp, tar, dd, cpio or what, and so on)? What advice would you give a future archivist to help them quickly classify bit copies of tapes :). Thanks, Will -- GPG Fingerprint: 68F4 B3BD 1730 555A 4462 7D45 3EAA 5B6D A982 BAAF