Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!purdue!decwrl!labrea!eos!ames!lll-winken!uunet!mcvax!unido!tub!tmpmbx!netmbx!hase
From: hase@netmbx.UUCP (Hartmut Semken)
Newsgroups: comp.sys.atari.st
Subject: Re: Writing on write-protected disk confirmed
Message-ID: <2481@netmbx.UUCP>
Date: 30 Mar 89 16:03:18 GMT
References: <1608@orion.cf.uci.edu> <769@snjsn1.SJ.ATE.SLB.COM>
Reply-To: hase@netmbx.UUCP (Hartmut Semken)
Organization: netmbx Public Access Unix, Berlin, West Germany
Lines: 30

In article <769@snjsn1.SJ.ATE.SLB.COM> greg@sj.ate.slb.com (Greg Wageman) writes:
>A while ago there was a posting stating that it is possible to write
>on a disk with the write-protect hole open (write-protected).  Most of
>us were skeptical, wanting to see schematics to know if this was, in
>fact, possible.


Whether this is possible or nor depends on the drive used.

My Teac FD55F and Mitsumi 3.5 inch floppy do not write to
write-protected disks.

If I disconnect the -WR line from the drives to the ST and pull it up
(10kOhms to +5Volts) on the ST side, the ST 'writes' to the disk, but
rereading it displays an unchanged directory. Nothing really gets
written.

The read/write amplifier in the Teac is disabled by the internal
WriteProtect signal. So it is not possible to write to write protected
disks.


Some NEC 1036 and 1037 do write to writeprotected disks (confirmed);
my Aplle Disk ][ (with an Apple ][) does the same...

hase
-- 
Hartmut Semken, Lupsteiner Weg 67, 1000 Berlin 37 hase@netmbx.UUCP
If there is something more important than my Ego, I want it caught and shot.
Now! (Zaphod Beeblebrox)