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From: mat@zelator.UUCP (Matthias Barmeier)
Newsgroups: alt.msdos.programmer,comp.sys.ibm.pc.programmer
Subject: Re: Why won't DOS allow more than 20 open files?
Message-ID: <623@zelator.UUCP>
Date: 13 Jun 90 07:06:44 GMT
References: <90160.191651JXS118@psuvm.psu.edu>
Reply-To: mat@zelator.UUCP (Matthias Barmeier)
Organization: Andreas Baumann Berlin, West Germany
Lines: 22

In article <90160.191651JXS118@psuvm.psu.edu> JXS118@psuvm.psu.edu (Jeff Siegel, Op from Atherton Hall) writes:
]Even though I have the statement FILES = 40 in my config.sys, DOS refuses
]to open more than 20 files at once and returns error code 4 (no handles
]available) if I try to open more. I've tested this on 3 different version
]of DOS (all of which allegedly support the FILES statement) Any clues why this
]is?

Try this :

MSDOS INT 21 with AX=6700h and BX=Number of handles to open.

This Msdos function returns in AX the error code if carry flag is set.
This call allows programs to control number of file handles available fo use.
Memory is allocated from memory freed by int 21 AX=4A00h. If number of handles
is less than current number of open files, change becomes effective when currentnumber of files drops below new limit.
INT 21 with AX=4A00h and BX=New requested block size in paragraphs (16 Byte).
                     and ES=Segment of Block to be modified.

I hope this will help you !

Ciao
   mat@zelator.UUCP