Re: Memory being incorrected sized at boot-up

Larry M. Augustin (
Fri, 11 Jul 1997 09:56:18 -0700

Please talk to me about this offline. I'm the author of the 2.0.30
memory detection code. I think what's happening is the that Compaq
BIOS reports only 16MB of RAM for the int 15h, ah=0x88 BIOS call on
the Compaq. The fix for this is to change the BIOS detection code to
use the 0xe801 call first, and then fallback if this fails.

I'll put together a fix for this and send it to you to test.


>Date: Fri, 11 Jul 1997 08:46:21 +0300 (EET DST)
>From: Kim Enkovaara <>
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>On Thu, 10 Jul 1997, Nicholas J. Leon wrote:
>> I recently popped a copy of Linux (2.0.30) on my Compaq Deskpro 2000 at
>> work and was amazed to see that it incorrectly reported the amount of RAM.
>> The box contains 32MB, but the kernel only sees 16MB.
>> Yes, I know, lilo append="mem=32M".
>I noticed this also with Deskpro 2000 and mailed to Compaq Support. I told
>them that I run Unix system with the computer and they answered to load
>dos program do correct the reporting in dos :) It's a bug in their bios I
>guess, because that dos program fills some values to system memory table.
>SP1835.EXE -- 38 K -- (17 May 96)
> SHOWEXT.COM version 1.50 enables Compaq computers to report all
>extended memory up to 64 megabytes in DOS
> instances of Windows 3.X & Windows 95 using the MEM.EXE DOS program.
>The above is accomplished by querying
> XMS and writing the value to a system memory table. SUPERSEDES:
>I sent them more mail asking what is their recomended way to query memory
>and never got answer back. At least the normal function int 15h/ah=88h
>doesn't work, It returns the 16M value. Maybe I should be nasty and begin
>calling the customer support and wonder why the machine can't find the
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