Article View: comp.sys.ibm.pc
Article #41016Write protecting hard disks
From: Chris Irie
Date: Mon, 08 Jan 1990 18:45
Date: Mon, 08 Jan 1990 18:45
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1351 bytes
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?
Thanks for your time...
-- Chris Irie
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arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!samsung!sol.ctr.columbia.edu!cica!iuvax!maytag!aries5!ckirieReferences:
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!samsung!sol.ctr.columbia.edu!cica!iuvax!maytag!aries5!ckirie From: ckirie@aries5.uucp (Chris Irie) Newsgroups: comp.sys.ibm.pc Subject: Write protecting hard disks Keywords: protect harddisk Message-ID: <1098@maytag.waterloo.edu> Date: 8 Jan 90 18:45:15 GMT References: <25a49409@ralf> Sender: daemon@maytag.waterloo.edu Reply-To: ckirie@aries5.UUCP (Chris Irie) Organization: Computer Systems Group, University of Waterloo Lines: 22