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Article #3526Re: LASTDRIVE function/asm/ect... Need one!
From: David Nye
Date: Sun, 08 Nov 1992 21:58
Date: Sun, 08 Nov 1992 21:58
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There is source code for this in the disk that accompanies the book Undocumented DOS by Andrew Schulman et al. Every programmer who writes under DOS should have a copy. I don't think the code is PD so I can't post it. Basically, you call Int 21h fn 19h to get the current drive and then Int 21h fn 0Eh to select that drive. As a byproduct of doing this, LASTDRIVE is returned in AL. Bear in mind that LASTDRIVE does not contain the number of drives in the system, only the size of the array built to hold disk information (the Current Directory Structure array). There often are fewer drives than LASTDRIVE, and may be more if the machine is networked. The only reliable way to actually count drives is to walk the Drive Parameter Block chain. David Nye nyeda@cnsvax.uwec.edu
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Path: arc1-ca.pugleaf.net!sparky!uunet!noc.near.net!hri.com!spool.mu.edu!yale.edu!jvnc.net!princeton!rutgers!uwvax!zazen!uwec.edu!nyeda From: nyeda@cnsvax.uwec.edu (David Nye) Newsgroups: comp.os.msdos.programmer Subject: Re: LASTDRIVE function/asm/ect... Need one! Message-ID: <1992Nov8.155834.2200@cnsvax.uwec.edu> Date: 8 Nov 92 21:58:34 GMT References: <1992Nov8.081922.15576@ra.msstate.edu> Organization: University of Wisconsin Eau Claire Lines: 15