DEIL_CLAYTON_BLAND@cup.portal.com (02/16/88)
The index hole tells the disk controller where sector zero begins! All floppy disk have them! Hard disk have them also but you cannot see them. Most drives have a LED and photo cell arangement to mark the start of secctor zero. If you want to realy mess up your system try using a photografic strobe during a disk read or write!! Deil Bland Stone Mountain, Ga
johnm@mist.cs.orst.edu (John Matzka) (02/18/88)
In article <3255@cup.portal.com> DEIL_CLAYTON_BLAND@cup.portal.com writes: >The index hole tells the disk controller where sector zero begins! >All floppy disk have them! >... Although this little hole does serve as a reference point for SOME drives, not all disks have them. I just bought a large number of disks (okay 30) and none of them have these little holes and the disks work just fine. >Most drives have a LED and photo cell arangement to mark the start >of sector zero. >... I can't say what percentage of disk drives actually use this little hole but Apple ][ series doesn't and some IBM compatible units don't either. Also, an interesting(?) point. If there is only one (or none I suppose) of these little holes in the disk media, then the disk is soft sectored. If there are many of them then the disk a hard sectored. Just try using a hard sectored floppy in a drive which expects only soft sectored disks and vice versa. >Deil Bland John Matzka ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Internet: johnm@mist.CS.ORST.EDU | The opinions expressed here UUCP: {tektronix, hp-pcd}!orstcs!johnm | do not necessarily reflect ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| those of OSU, the CS dept. Everything that is not nailed down is mine. | or my supervisors. Anything I can pry loose is not nailed down. | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ John Matzka ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Internet: johnm@mist.CS.ORST.EDU | The opinions expressed here UUCP: {tektronix, hp-pcd}!orstcs!johnm | do not necessarily reflect ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| those of OSU, the CS dept. Everything that is not nailed down is mine. | or my supervisors. Anything I can pry loose is not nailed down. | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~