[comp.sys.ibm.pc] There's a hole in my floppy, dear Liza, dear Liza

madd@bu-cs.BU.EDU (Jim Frost) (02/16/88)

In article <9544@steinmetz.steinmetz.UUCP> iraq!halvers@steinmetz.UUCP (peter c halverson) writes:
>>Well, I just found
>>out that all floppies have that hole.
>
>I took a look at my software
>collection, and *every* *single* *disk* has a hole in it.
[...]
>Has anyone else noticed this, or is there something wrong with all
>of my disks?  Could this have anything to do with these "virus" programs
>that I keep hearing about?

Before this gets out of hand....

The hole in the floppy is supposed to be there.  It has nothing to do
with virus programs, and in general virus programs cannot put a hole
in your disk (unless of course you have your optional laser installed
in your PC, but I suspect many people do not).

There are two forms of diskette, those with one hole in them and those
with many.  Diskettes with many holes are "hard sectored", meaning
that each hole indicates the start of a sector.  Most drives now use
diskettes with only one hole, which indicates the first sector of the
track.  Some drives don't use the hole at all -- Apple 5.25" and
Commodore 1541/1571 drives are examples of these.

If you buy copy protected programs, you may notice that some of them
have a hole in the read/write area.  This has to do with a copy
protection scheme and is also supposed to be there.

If you want more information on diskettes, I recommend going to your
local library and looking up a Byte magazine issue that dealt almost
exclusively with diskettes.  I don't remember which issue it is, but
if you look through the archives you can't miss it.  It should be 1985
or 1986.

jim frost
madd@bu-it.bu.edu

bobmon@iuvax.UUCP (Bob...Mon) (02/16/88)

iraq!halvers@steinmetz.UUCP (peter c halverson) writes:
-  I took a look at my software
-  collection, and *every* *single* *disk* has a hole in it.
- [...]
-  Has anyone else noticed this, or is there something wrong with all
-  of my disks?  Could this have anything to do with these "virus" programs
-  that I keep hearing about?


Then madd@bu-it.bu.edu (Jim Frost) writes:
-  There are two forms of diskette, those with one hole in them and those
-  with many.  Diskettes with many holes are "hard sectored", meaning
-  that each hole indicates the start of a sector.  Most drives now use
-  diskettes with only one hole, which indicates the first sector of the
-  track.  Some drives don't use the hole at all -- Apple 5.25" and
-  Commodore 1541/1571 drives are examples of these.

I'm afraid you're both wrong.  Most 5.25" disks have _two_ holes in them;
a nice big one in the middle, which peter noticed, and a smaller, more
modest one that Jim caught on to.  I can personally attest that the Commodore
1541 drive ignores the absence of the little hole, from which I conclude that
it would also ignore the presence of the little hole.  The only time it ever
ignored the BIG hole, though, the disk became unusable thereafter.  This may
have been the work of one of those viruses that peter fears -- in my experience
disks _without_ that big hole in the center have been fairly immune to 
malicious disk writes.

p.s.  :)
-- 
RAMontante				bobmon@iuvax.indiana.cs.edu
Computer Science Department			If you listen to Tools...
Indiana University					the Slide Rules!