On Fri, 22 Oct 1999, Chuck McManis wrote: No. The L in DLT stands for "linear". It's also a big reason people prefer DLT to 4mm or 8mm tape. ok r.

Jerome Fine replies: Special thanks to Chuck McManis and Zane Healy for the URL and the information. Based on the data within the above tables (and at the URL), there seems no doubt that DEC practised their usual antics back in the 1980s when they practised their standard marketing policy of adding "nothing". From my experience with CompacTape and CompacTape II, I can definitely say that these two tapes ARE VERY DIFFERENT: The CompacTape is usually labelled with a BROWN designation and the CompacTape II is usually BLUE!! Does anyone remember if there was also a price difference between CompacTape and CompacTape II????????? Incidentally, on a PDP-11, my experience is that about 70 MBytes can be written using a TK50 and that takes about 50 minutes if streaming mode can be maintained. To verify that information took many hours. For a TK70, I have been able to write about 275 MBytes on the tape in about 1 hour and verification takes between 1 hour and 20 minutes and 2 hours depending on the hardware configuration and other things I do not understand - the key point is that verification is at worst, only twice as long. Sincerely yours, Jerome Fine

Jerome Fine replies: If you want the specifications for the various tapes that were called Compac I,II,III along with the DLT tapes, look at: http://www.anacomp.com/Magnetics/Memorex/m-ctdlt.html which provides all sorts of additional information. Is it possible that the price difference of between 40% and 50% that I see in a catalogue from about 10 years ago was solely for the change from a BROWN "CompacTape" designation to the BLUE "CompacTape II" designation? Just as some companies that offered different density floppy diskettes or double-sided diskettes at different prices but with the identical media and charged a premium price, I am somewhat suspicious that even if DEC followed different certification procedures for the CompacTape II vs those for the CompacTape that there would be even a noticeable difference in the cost of producing the CompacTape II. And without any evidence on your part that there were any certification levels for the CompacTape II that were different from those for the CompacTape (let alone that if there were some that they cost any more or that the cost amounted to any more than a few cents per CompacTape II), I suggest that you provide at least some proof that you know that such certification levels existed along with the actual additional costs. Incidentally, I noticed in the same 10 year old catalogue that DEC RX50 and DEC RX33 diskettes were also priced far above standard prices in the market for identical products. For example, the RX33 is identical to a PC HD 5 1/4" floppy, yet DEC was charging close to $ 50.00 per box of 10 RX33 simply because there was an RX33 label. I notice in the same URL reference that the "CompacTape III" was specified for all 3 tape drives: TK85, TZ86 and TZ87. Was it possible that DEC realized that the so-called "standard practice in the entire disk and tape media industry to offer the same media" for use in different drives such as the TK50/TK70 (BUT UNDER A DIFFERENT LABEL) was no longer reasonable and so long as the same media was going to be used for all 3 drives (BUT at substantially different capacity), it would be much more reasonable for all 3 tape drives to use the same media (a CompacTape III instead of III, IV and V)? All I am asking is that if you have actual proof that there were different certification levels for CompacTape and CompacTape II that you provide such proof along with the additional cost. Otherwise, I must assume that the only reason for the 40% to 50% increase in cost was the so-called "standard practice in the entire industry" of charging more when it was possible to do so. I realize that DEC produced both hardware and software products of superior quality.... BUT.... Sincerely yours, Jerome Fine