Jerome Fine replies: There used to be a site which listed the physical and electrical characteristics of all the DLT tapes - sadly it is no longer available. However, the table showed that the ONLY TWO differences between a CompacTape (I) and a CompacTape II were the price and the colour of the label - Brown for the CompacTape and Blue for the CompacTape II. DEC usually charged a considerable premium when the label was Blue. As Zane mentioned, its is definitely possible to bulk erase a CompacTape I or II after a TK50 has written to the blank tape (at which point a TK70 will no longer write to the tape since the TK70 drive immediately places it in WRITE PROTECT). I think a friend has a few that can be spared at this point - e-mail me privately and I will make the contact after I know a bit more. He sold me a few for my TK70 and they work very well! By the way, the TK70/TQK70 is a reasonable combination. While I use RT-11 which can write files of a maximum of 32 MBytes, that can be done in about 7 Minutes at full streaming mode. Even a compare can also be done in full streaming mode in 7 minutes. Both times were for that 32 MByte file and when BUP is used. When I use BUP (8192 byte records), the capacity of a TK70 is about 300 MBytes or about 8.75 RT-11 partitions. If you can find a bulk eraser, be careful. Evidentially my friend went through quite a few - burned them out since they are not designed for continuous use unless you purchase the expensive ones - which I presume you want to avoid in the first place. Sincerely yours, Jerome Fine