Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!pacific.mps.ohio-state.edu!linac!att!news.cs.indiana.edu!widener!netnews.upenn.edu!vax1.cc.lehigh.edu!cert.sei.cmu.edu!krvw
From: jesse%altos86.Altos.COM@vicom.com (Acer - Jesse Chisholm)
Newsgroups: comp.virus
Subject: Re: can we trust diskette write-protection? (PC)
Message-ID: <0008.9105061316.AA01852@ubu.cert.sei.cmu.edu>
Date: 3 May 91 16:44:12 GMT
Sender: Virus Discussion List <VIRUS-L@LEHIIBM1>
Lines: 14
Approved: krvw@sei.cmu.edu

PHYS169@csc.canterbury.ac.nz (Mark Aitchison, U of Canty; Physics) writes:
| Possibly, the reason why it sometimes fails, other than obvious loose
| wires, is because of light bouncing around the diskette drive.
| ...
| Someone may be able to answer the
| question as to whether the circuitry uses synchronised pulsed light,
| or plain light (the latter would mean daylight from outside the
| computer could nullify the protection system).

I don't know about the pulsed or steady light, but I do know that if I
leave the cover off my machine, the flourescent lights totally confuse
the drive as to whether there is or isn't a write protect tab on the
floppy.  I have had no trouble with silvered tabs, but then, the brand
I buy usually comes with black ones.