Xref: utzoo comp.sys.ibm.pc:35897 alt.msdos.programmer:484
Path: utzoo!attcan!uunet!portal!cup.portal.com!Wes
From: Wes@cup.portal.com (Wes H Cowley)
Newsgroups: comp.sys.ibm.pc,alt.msdos.programmer
Subject: Re: How much memory is left during execution?
Message-ID: <22865@cup.portal.com>
Date: 7 Oct 89 23:52:51 GMT
References: <3178@tekcae.CAX.TEK.COM>
Organization: The Portal System (TM)
Lines: 13

This isn't considered "well-behaved", especially if you're going to ever move
the code to a multitasking environment, but you can use Int 21h function 48h
to request more memory than the system has.  One of the return values will
tell you how much is available.

	Call with: AX == 48h
		   BX == FFFFh
	Return:
		   AX == 08h (Insufficient memory)
		   BX == Size of largest memory block available.

This won't give you total memory available if memory is fragmented, but in
most cases will tell you most of the available memory.