Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!cica!ctrsol!ginosko!uunet!zephyr!tektronix!psueea!parsely!bucket!leonard
From: leonard@bucket.UUCP (Leonard Erickson)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Dedicated memory ?
Keywords: extended memory, olivetti
Message-ID: <1561@bucket.UUCP>
Date: 16 Jul 89 00:07:44 GMT
References: <8167@bsu-cs.bsu.edu> <1171@calvin.EE.CORNELL.EDU> <5486@pt.cs.cmu.edu> <23573@santra.UUCP>
Distribution: comp
Organization: Rick's Home-Grown UNIX; Portland, OR.
Lines: 38

s32935k@taltta.hut.fi (Carl Torsten Stenholm) writes:

<I just purchased an *livetti (I think the number was M380), anyway it has:

<	80386, 81 M harddisk, 20 MHz clock, 1 M memory.

<The problem is this 1 M memory. The startup system check tells me:

<	Main memory     640 K  OK
<	Dedicated Mem	384 K  OK

<I just cant use these 384K of "dedicated memory". I called the dealer
<and he told me "I am sad to inform you, you just cannot use it".
<I find this very hard to believe. The memory check reads and writes to
<it -- so it must be possible to adress it. If it were not -- how can it
<be called memory ?
<Anyway -- If it is adressable, then it must be possible to use it as
<a virtual disk par example. MS-D*S 3.3 vdisk and cacher both fail to find
<this (Using the /E flag).

Sorry, but many machines do this sort of thing. That memmory is addressed
the 640-1024k range. This area is already used by *other* things like video
boards, hard disk controllers, the BIOS ROMs, etc.

Since your machine tests it, rather than ignoring it, it may be mapping
the ROMs to this memory to improve performance. (RAM reads are faster
than ROM reads). 

The Reason the /E option on vdisk didn't work is that it is for accessing
*extended* memory. Extended memory starts above the 1 meg mark. 

In short, if it can be used for something, the system is already doing so.

-- 
Leonard Erickson		...!tektronix!reed!percival!bucket!leonard
CIS: [70465,203]
"I'm all in favor of keeping dangerous weapons out of the hands of fools.
Let's start with typewriters." -- Solomon Short