Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!usc!snorkelwacker!ira.uka.de!smurf!gopnbg!tmpmbx!einoed!utopia!neon!pwendt
From: pwendt@neon.UUCP (Patrick Wendt)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Write protecting hard disks
Keywords: protect harddisk
Message-ID: <896@neon.UUCP>
Date: 14 Jan 90 20:46:20 GMT
References: <25a49409@ralf> <1098@maytag.waterloo.edu>
Organization: Neon Research Caboose (tm)
Lines: 41

Hi !
====

ckirie@aries5.uucp (Chris Irie) writes:

>Does anyone know how to write protect (logical) harddisks on the fly?
>Here are some thoughts so far:

>        1. Intercept BIOS INT 13 calls. Works fine for floppy disks.
>           Problem is with hard drives that are partitioned. In that case,
>           you have to read the partition table to figure out which logical
>           drive dos is talking about. This seems like a lot of work.

>	2. Intercept DOS INT 25/26 (Absolute read write).
>           Turns out that these are not called all the time (sometimes DOS
>           goes straight to INT 13).

>	3. Intercept DOS INT 21.   
>           Would require knowledge of all INT 21 calls. Implies a lot of
>           parsing, knowlegde of FCBs, etc.

>Is there a commercial package that does what I want? 

Yes, there are commercial packages for that, I have two programs
on my hard-disk(s), that lock the HD quite good ...
Maybe I'll mail you per UUENCODE if you are interested ?
Or I'm disassembling it, and send you the source.

Contact me if you're interested.

>Thanks for your time...

No problem :-)

Greetings ... Pat !

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