Path: utzoo!utgpu!utcsri!mendell
From: mendell@utcsri.UUCP (Mark Mendell)
Newsgroups: comp.sys.ibm.pc
Subject: Detecting write-protected diskette on PC, AT, etc
Message-ID: <5729@utcsri.UUCP>
Date: 11 Dec 87 22:22:46 GMT
Article-I.D.: utcsri.5729
Posted: Fri Dec 11 17:22:46 1987
Distribution: na
Organization: CSRI, University of Toronto
Lines: 24


    Is there any way to detect a write-protected diskette without trying to
do a write to the diskette?  I have read the relevant parts of Norton's
Programmers guide to the IBM PC, and have experimented with the BIOS call
Get diskette status (0x1).  I am already using the Verify Diskette Sectors
(0x4) interrupt to check for the presence of a formatted diskette.  That works
perfectly for that purpose.

    I am trying to detect if a later open will fail, without having to 
write a critical error handler to detect the un-writable diskette.

    Is there any DOS or BIOS call that will return the information for me?

    Please mail any responses to me.


Thanks

-- 
Mark Mendell
	    Computer Systems Research Institute    University of Toronto
	    Usenet:	{linus, ihnp4, allegra, decvax, floyd}!utcsri!mendell
	    CSNET:	mendell@Toronto
	    ARPA:	mendell%Toronto@CSNet-Relay