tim@doug.UUCP (Tim J Ihde) (12/29/87)
I am approaching my frustration limit w.r.t. trying to read and write to high-density disks on my quad-density (96tpi) drive. While I get no error writing to hd disks, they can not then be read on various xt's about. Similarly, I am usually unable to read these disks if written by xt's. Ok, I know this has always been a flakey thing. My next step was to try to install a spare hd drive that I have had laying around for some time (since I stuck a hard disk in by pc clone). I was suprised to find that the mounting rails were wrong, and the connector seemed to be in the wrong place. This cannot be corrected without a reasonable amount of effort, and I don't really want to muck about in there TOO much. So, my question is: is there a real internal difference between high density disk drives as used in the standard PC models and those used by AT's ? I don'really think this is likely, so my next question is whose bright idea was it to change the rail/connector format - IBM or my manufacturer (not ibm) ?? These days floppys are not very expensive, but if I must go out and buy another while leaving my spare in the closet I would like to know who to thank, not to mention who I must buy it from. tim -- Tim J. Ihde ihnp4!ctsmain!doug!tim (201) 535-9897 Ok, we can all agree that this is my fault.
loafman@convexe.UUCP (12/30/87)
/* Written 9:41 am Dec 29, 1987 by tim@doug.UUCP in comp.sys.ibm.pc */ /* ---------- "High density drive in AT (not quad)" ---------- */ > I am approaching my frustration limit w.r.t. trying to read and write > to high-density disks on my quad-density (96tpi) drive. While I > get no error writing to hd disks, they can not then be read on > various xt's about. Similarly, I am usually unable to read these disks > if written by xt's. A couple of facts that may answer your questions. - an HD diskette may only be read on an HD drive. (obvious) - a DD diskette may be formatted and written on an HD drive, but it will more than likely have problems when being read from a DD drive. So, if you are trying to format and write DD diskettes on an HD drive, then take them to be read on a DD drive, you will be out of luck. Moderate luck can be obtained if the DD disk is formatted on a DD drive. Some (but not all) HD drive/controller combinations will write DD to that previously formatted diskette if the phase of the moon is just right. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Kenneth W. Loafman @ CONVEX Computer Corp, Dallas, Texas | All opinions Voice: work: (214) 952-0829 home: (214) 964-1250 | are my own, USPSnail: 1705 Coit Rd #2101, Plano, Tx 75075 | of course. UUCP: ihnp4!convex!loafman | ...KWL ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
wtm@neoucom.UUCP (Bill Mayhew) (01/04/88)
<<HD diskettes in a quad density drive>> HD diskettes can not be written upon in either a 360K or a quad density drive. This is because the magnetic material used in HD disks requires a much stronger magnetic field to write. The heads in standard drives don't have enough field strength to work. A brand new double density floppy may be formatted and written in an HD drive. They can probably be read in a 360K drive, but if you mix and mach by writing with but drive types on the same diskette, you will almost certainly eventually get read errors due to differing track widtch used and alignment skew on 360K drives. There are some software packages advertised that claim to enable an HD drive to successfully format and write in interchangable 360K format. They do this by recording the same data track 4 times in the HD drive. I haven't tried any of these programs, so you are on your own... --Bill
dave@westmark.UUCP (Dave Levenson) (01/06/88)
In article <63200021@convexe>, loafman@convexe.UUCP writes: > > /* Written 9:41 am Dec 29, 1987 by tim@doug.UUCP in comp.sys.ibm.pc */ > /* ---------- "High density drive in AT (not quad)" ---------- */ > > I am approaching my frustration limit w.r.t. trying to read and write > > to high-density disks on my quad-density (96tpi) drive. While I > > get no error writing to hd disks, they can not then be read on > > various xt's about. Quad-density (720 kbytes / diskette) is not compatible with either High Density (1.2 Mbytes / diskette) or Double Density (360 kbytes / diskette). The AT-compatible High Density drives and controllers are capable of writing either HD or DD format, but not QD format. If you're really using QD media, buy some DD or HD media, and I think your problems will be solved. -- Dave Levenson Westmark, Inc. The man in the Mooney. Warren, NJ USA {rutgers | clyde | mtune | ihnp4}!westmark!dave