gyao@polyslo.CalPoly.EDU (Ginlom Bob Yao) (06/27/91)
Hi, There's a problem in my pc: When i insert a floppy in drive A and type dir, it always comes out the former contents (which is the first one after reboot. It doesn't matter how many times i change other floppys later.) I can use Ctrl-c and dir again to solve this problem (But i have to do each time whenever i wanna use dir in drive A). Could you give me some hints about this problem? I'll be appreciate! Thanks! Bob
cwinemil@keys.lonestar.org (Chris Winemiller) (06/29/91)
gyao@polyslo.CalPoly.EDU (Ginlom Bob Yao) writes: > When i insert a floppy in drive A and type dir, it always comes out > the former contents (which is the first one after reboot. > It doesn't matter how many times i change other floppys later.) I can use > Ctrl-c and dir again to solve this problem (But i have to do each time > whenever i wanna use dir in drive A). > > Could you give me some hints about this problem? I'll be appreciate! Bob, There is a mechanism in your floppy drive which detects "change of media"; i.e., it signals when a floppy has been removed/inserted. DOS uses this info; it stores your floppy's "directory" info in memory and uses _that_ instead of reading your floppy each time. When the floppy is changed out for another, DOS detects it and then reads the disk itself and stores its info. Now, if the "change of media" signal from the drive is broke, it may think that there's "always" a floppy inserted and never changed out! This happened to me recently. You can either: 1) try to fix the drive; or 2) buy another drive for $70 or less. I did the latter, because I'm a klutz at repairs :-). > Thanks! Your welcome! Chris -- Chris Winemiller Internet: cwinemil@keys.lonestar.org UUCP : texsun!letni!keys!cwinemil texsun!digi!keys!cwinemil
valley@gsbsun.uchicago.edu (Doug Dougherty) (06/29/91)
cwinemil@keys.lonestar.org (Chris Winemiller) writes: >gyao@polyslo.CalPoly.EDU (Ginlom Bob Yao) writes: >> When i insert a floppy in drive A and type dir, it always comes out >> the former contents (which is the first one after reboot. >> It doesn't matter how many times i change other floppys later.) I can use >Bob, > There is a mechanism in your floppy drive which detects "change of >media"; i.e., it signals when a floppy has been removed/inserted. DOS >uses this info; it stores your floppy's "directory" info in memory and >uses _that_ instead of reading your floppy each time. When the floppy >is changed out for another, DOS detects it and then reads the disk >itself and stores its info. Now, if the "change of media" signal from >the drive is broke, it may think that there's "always" a floppy >inserted and never changed out! This happened to me recently. You can Interestingly enough, this happens to me frequently (but not always), when I switch diskettes *if* I do the switch quickly. If I wait a few seconds between removing the first and inserting the next, it will be OK. There is a statement in one of the DOS programming manuals to the effect that "it is impossible to switch a disk in less than two seconds" and DOS uses this fact to determine whether the diskette has been changed. I wonder if I'm just fast, or if some drives/versions of DOS stretch this two seconds out a bit. -- (Another fine mess brought to you by valley@gsbsun.uchicago.edu)