No - can't use it for ZX128 paging - as SAM's is rather different layout
----- Original Message ----- From: "Aley Keprt" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Friday, August 03, 2001 11:22 AM Subject: Re: External memory on Sam > 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? > > ------------------------------------------------------------------ > Bc.Aley [eili] Keprt - games & multimedia programmer > ICQ: 82357182 (evenings) *** phone: +420-68-5387035 (weekends) > private e-mail: [EMAIL PROTECTED] *** http://get.to/aley > office: Illusion Softworks, Brno, CZ - [EMAIL PROTECTED] > ------------------------------------------------------------------ > > ----- 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 > > > > >
