Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!samsung!balrog!ctron.com
From: dj@ctron.com (DJ Delorie)
Newsgroups: comp.os.msdos.programmer
Subject: Re: Discovering DOS 4 Disk Space?
Message-ID: <1509@balrog.ctron.com>
Date: 20 May 91 13:27:31 GMT
References: <1991May9.180001.48119@ccvax.ucd.ie>
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Reply-To: dj@ctron.com
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In article <1991May9.180001.48119@ccvax.ucd.ie>, h235_131@ccvax.ucd.ie writes:
> Sorry if this is a FAQ, but can someone tell me how to check disk-space
> on *big* DOS partitions (ie 32-bit under DOS >=V4.0)?
 
> I know about INT 21h fn's 1Bh, 1Ch & 36h but they all return the # of
> available clusters as a 16-bit number - did Microsoft limit the # of
> clusters to 64K?

This function works properly, and yes, there is a 64K limit to the
number of clusters.  However, the clusters can get *huge*.

Use this function, but cast to 32-bit values *before* multiplying
them together, and you'll get a correct result.

DJ
dj@ctron.com