Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!mit-eddie!bloom-beacon!eru!hagbard!sunic!news.funet.fi!hydra!cc.helsinki.fi!juseppala
From: juseppala@cc.helsinki.fi
Newsgroups: comp.os.msdos.programmer
Subject: Re: insert diskette in drive B
Message-ID: <1991Feb24.193017.5151@cc.helsinki.fi>
Date: 24 Feb 91 19:30:16 GMT
References: <090905.3866@timbuk.cray.com> <666@sun4dts.dts.ine.philips.nl>
Organization: University of Helsinki
Lines: 21

In article <666@sun4dts.dts.ine.philips.nl>, derek@sun4dts.dts.ine.philips.nl (derek) writes:
> I'm doing this from memory, no docs with me, which is why I'm posting rather than 
> mailing this reply, in th ehope that someone will fill in the details I have to
> leave out.
> 
> At a certain MS-DOS release (3.2 I think) an IOCTL subfunction was added which
> would allow you to check if the current logical drive was the last one accessed
> (remember drive A: is always accessed at boot). Anyway this is exactly the
> function (DOS interrupt that is) that you want. Do the interrupt, get the
> result, then access the disk, or change the logical drive yourself, if you 
> need too. 

Interrupt 21h, function 440Eh. AH = 44h, AL = 0E, BL = drive number to
be inquired. Returns the last used drive number in AL. I think this is
the contents of address 0040:0104.
-- 
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