It is a great piece of hardware.
Similar to Amiga. Only CPU access, but well pageable, usable to achieve 6MHz
speed, and allows to emulatoe ZX Spectrum 128 paging. Am I right.
Master Dos seems to use it for its own.
That is probably what I talked about recently. Simon Cooke wrote that I am
missing the point, when wanting this from 80's designed computer Sam Coupe.
But here I can see it is real. So why don't we have at least 256KB internal
memory made of this external one?
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Bc.Aley [eili] Keprt - games & multimedia programmer
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----- Original Message -----
From: "Simon Owen" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: 3. srpna 2001 12:02
Subject: RE: External memory on Sam
> Aley Keprt wrote:
> > Is external memory contended?
>
> Nope.
>
>
> > Or how does it work? Is it possible to page it into 64KB CPU
> > space, and then let CPU run at 6MHz in there?
>
> Well, it can only be mapped into the upper 32K, not the full 64K address
> space (still be good enough for a lot of stuff). Depends whether you
> were thinking about general programs using it, or getting the BASIC
> system to use external memory instead of contended system RAM. The
> display will always be in system RAM, so you'd have to write to it in
> the border area to escape as much contention as possible!
>
> Not many people have external RAM though, so I can't imagine any
> existing software would/could rely on it for the extra speed. It'd
> certainly screw up fancy demo timings too!
>
> Si
>
