RE: TI-H: DriverLESS Memory Expander

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RE: TI-H: DriverLESS Memory Expander

Well, there IS a way, but the calc would become incredibly difficult to work with.
Step 1:  An assembly driver to handle the pages (Usgard TSR most likely)
each page would be a standard page to the calc, VAT, graphmem, etc.
Hit a key sequence, and BOOM!  your memory seems wiped clean.  What really happened was that it transferred the contents of RAM to a buffer and transferred a different page in to the main RAM.  Of course, you can't have contiguous memory or anything as useful as that, and you may even need your standard OS on each "page", but it would do the trick.
But at this point, GET AN EXPANDER.  It's the almost the same thing.

Christopher Kalos
raptorone@stuytech.com
Executive Director/Administrator
Virtual Technologies Developer's Group


----------
From: 	Grant Stockly[SMTP:gussie@alaska.net]
Sent: 	Monday, November 17, 1997 6:06 PM
To: 	ti-hardware@lists.ticalc.org
Subject: 	Re: TI-H: DriverLESS Memory Expander

>At 08:59 PM 11/16/97 -0700, Grant Stockly wrote:
>
>>Well, that wouldn't add more than about 32k.  The rom in the calcs doesn't
>>even support more than that.  It would take a long time, and your warntee
What I meant to say, was that the calc doesn't support more than the
orrigional 32k (27.5k) and adding more is impossible.

>>would void.
>>
>>>what about adding directly to the existing memory in the calc so that it
>uses
>>>the existing MAP.?  Im surprised nobody has devised a lan to take care of
>>>that.
>
>Actually it would be impossible.  The ROM is addressed in from $0000-$3FFF
>for page 0 and $4000 to $7FFF for pages 1 to 7.  The RAM is addressed from
>$8000 to $FFFF (including stack and video mem).  Because the Z80 can only
>use 16-bit addresses that's all the memory it can address.  The TI-86 uses
>RAM pages, but this would be impossible on the 85 because even if you added
>it, the ROM wouldn't support it.
>
>
>--
>Brian Leech
>butvis@mindspring.com
>ICQ UIN: 1355611
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