Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!hp4nl!phigate!prle!prles2!hijg!johnj From: johnj@hijg.prl.philips.nl (John Janssen) Newsgroups: comp.sys.atari.st.tech Subject: Re: HD and DD floppies (Was: FTP problems) Message-ID: <2649@prles2.prl.philips.nl> Date: 3 Apr 91 11:46:23 GMT References: <2631@prles2.prl.philips.nl> Sender: news@prles2.prl.philips.nl Reply-To: johnj@hijg.UUCP (John Janssen) Organization: Philips Research Laboratories, the Netherlands Lines: 88 In article you write: >> Excerpts from netnews.comp.sys.atari.st.tech: 25-Mar-91 HD and DD >> floppies (Was: FT.. John Janssen@hijg.prl.ph (1804) > >> 2. The material structure of the floppies is somewhat >> different. (Note: I'm not an expert in this latter area). > >Nope, on both counts. You are not an expert :^), Yep you are right, I am not a material engineer, just an hardware and software engineer. and there is absolutely >no material difference between the two disks. This is a big lie from the >disk makers to charge way too much for DS/HD disks. The only difference >between the two, besides the extra hole, is that there are *sometimes* >extra quality check on the DD and HD disks. I think you are wrong here! There are differences, as I work a lot with both HD and DD floppies and floppy drives, and their differences drives me crazy-). It is almost impossible to use HD floppies with DD drives. You are really asking for troubles. Ok, I know there are exceptions, dependent on the brand. The only good results I had were with '3M' HD floppies, but then (see my original posting) format them with a DD drive, as this seems very important. I am talking about *REAL* experiences, and that learned me that most brands have different type of floppies for DD and HD. You do not need to take my advice, and learn it the hard way if that's what you want. My advice was only for all other souls around, who doesnot want to loose important files and waste their time by finding it out eventually. Actually, even SS disks are >the same. If they are given the hole, you can format SS disks to HD with >no porblems. They (disk makers) just manufacture a batch of floppies, >set aside a bunch to fill the SS order, and then test them for SS >integrity. Then they fill their DD order, and test them, Yep you are right here, but I was not talking about Single and Double Sided (SS and DS respectively), but about Double Density and High Density (DD and HD resp.). then they fill >their HD order, and test them, all from the same batch. As the error >rate in manufacture is fairly constant, the chances of a SS disk going >bad are not that much more than off the shelf HD disks. And here you go wrong again imo (see above). This is why >large fortune 500 corporations use devices like DiskDoubler to save >money, and buy SS or DD disks. > -geisha- Yep you are right again, as i think you are talking about one or two sides again. Note: a lot of different computers, a lot of different drives, a lot of different floppies, all from different brands were involved in our experience over a period from more than a year. So again, believe it or not. It's up to you! I only know the problems we had and the way we found (see original posting) to continue our actual work (which had nothing more to do with floppies than just being a storage medium). I just wanted to share our experience for those who wanted it. Success, John -- John Janssen Check the email address in the header, as this J.v.Deventerstr.1 may have been filled in wrong by the system. Venlo Holland +31 77 513177 Reply to: johnj@idms.prl.philips.nl