From: Paolo Ornati <javaman@katamail.com>
To: herbert@13thfloor.at
Subject: Re: [OT] Documentation for PC Architecture
Date: Mon, 18 Aug 2003 23:11:53 +0200
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>
> > Curiosity: since the memory addresses from 640KB to 1MB are reserved for
> > memory mapped I/O (video memory) and BIOS ROM... the corrispondent range
> > in
>
> uh oh ...
>
> > the REAL MEMORY isn't usable and so we lost 384KB of memory. Is this
> > right?
>
> for DOS, withouth upper memory manager yes ;)

I'm talking about an OS in protected mode... in any case how can I access to 
this memory region if it's mapped for other things?

I've done some tests with a simple kernel which I wrote: all that region 
(except video memory at 0xb8000) results "read only"...

So I THINK YOU mean: "you can use more than 640KB in real mode using a memory 
manager that "remap" 0xC0000 (for example) to 0x100000 or something like it"

Right?

bye,
	Paolo

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