TK50 / TK70 Media Differences

Has anyone any explicit knowledge and / or experience of a TK70 tape drive on a PDP-11? In respect of the media, does anyone know of any explicit differences between a TK50 (CompacTape) and a TK70 (CompacTape II)? Memorex used to have a page listing all DLT physical and magnetic characteristics. At the time, I was unable to see any differences. I did find some data starting with DLT III media, but not for TK50 / TK70: http://www.data-storage.co.uk/tape/quantum/media.htm Can anyone at classiccmp help answer these questions? My personal experience over the last 15 years using a TK70 on a PDP-11 under RT-11 is that regular TK50 media (CompacTape) have always been successfully used (over 100 TK50 media) with the TK70 tape drive (after the TK50 media are bulk erased if they were ever placed into a TK50 tape drive - if they were completely unused, they worked immediately). Sincerely yours, Jerome Fine -- If you attempted to send a reply and the original e-mail address has been discontinued due a high volume of junk e-mail, then the semi-permanent e-mail address can be obtained by replacing the four characters preceding the 'at' with the four digits of the current year.