[comp.virus] Floppy disk detection

UMEEM37@VAXA.CC.IMPERIAL.AC.UK (Olivier M.J. Crepin-Leblond) (01/10/91)

>From:    Douglas Barlow <DOUGB@comsys.byu.edu>
>> From:    Mr Gordon S Byron <gsb1@forth.stirling.ac.uk>
>>
>> I am interested in finding a DOS antivirus program which would
>> automatically scan disks as they are inserted. ideally, something like
>> SAM II on the Mac. I noticed a reference to a program called McAfee's
>> scan. Is that an auto-scan antivirus program?
>
>Only one problem with that idea: How can the machine tell when a disk
>is inserted?  There isn't any type of sensor in IBM floppy drives like
>in the Mac.
>
>Doug Barlow

	There are many types of 3 1/2 PC disk drives. Some drives
actually detect a disk as soon as it is inserted. This type is
recognizable when the shutter door of the disk is heard to slide as
soon as the disk is inserted. However, I think that the sensor is a
purely mechanical sensor (switch) which is connected to a solenoid of
some sort, which makes a small lever slide the shutter.  The second
type of 3 1/2 disk drive slides the shutter open only when the disk is
accessed for the first time after being inserted in the drive.
	What one would need, is some guidelines on the features a PC
disk drive should have. Because of the number of cheap clones around,
there is still a long way to go.

Olivier M.J. Crepin-Leblond,     Internet: <umeem37@vaxa.cc.ic.ac.uk>
Communications & Signal Processing , Electrical Engineering Dept.,
Imperial College of Science, Technology and Medicine, London, UK.
>> If nothing else works: take disk. take knife, use knife on disk.