Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!philmtl!ray
From: ray@philmtl.philips.ca (Raymond Dunn)
Newsgroups: comp.sys.ibm.pc
Subject: PS/2 Extended BIOS Data Area (Was: Re: 640KB + 3072KB = 4 MB?)
Message-ID: <709@philmtl.philips.ca>
Date: 18 Sep 89 15:10:14 GMT
References: <8909170749.AA26779@euler.Berkeley.EDU> <251419E0.1024@maccs.dcss.mcmaster.ca>
Reply-To: ray@philmtl.philips.ca (Raymond Dunn)
Organization: Philips Electronics Ltd. -  St. Laurent  P.Q., Canada
Lines: 16

In article <251419E0.1024@maccs.dcss.mcmaster.ca> cs4g6ag@maccs.dcss.mcmaster.ca (Stephen M. Dunn) writes:
>...
>[On a PS/2] DOS reports 639K conventional memory
>I find 640K
>
>Any ideas why?

This 1K of memory is grabbed from the top of the available memory by the PS/2
ABIOS as workspace, and is know as the Extended BIOS Data Area.

Its segment address can be got by calling INT 15 function C1.
-- 
Ray Dunn.                    | UUCP: ray@philmt.philips.ca
Philips Electronics Ltd.     |       ..!{uunet|philapd|philabs}!philmtl!ray
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