[Coco] Re: 64K Mode

[peak at mail.polarcomm.com]

Paul
How about showing us that TTL scheme(Piggy Back 64k)?
Did you use Dynamic ram? If so did the SAM refresh it ok?
Eric


---- Original message ----
>Date: Tue, 13 Jan 2004 22:44:35 -0800 (PST)
>From: "Paul T. Barton" <idezilla at yahoo.com>  
>Subject: Re: [Coco] Re: 64K Mode  
>To: CoCoList for Color Computer Enthusiasts 
<coco at maltedmedia.com>
>
>
>--- "John E. Malmberg" <wb8tyw at qsl.net> wrote:
>> jdaggett at gate.net wrote:
>> > John
>--snipped-- 
>> We are basically saying the same thing.
>> 
>> You have a choice of 64K Dynamic RAM, or upper
>> 32K ROM/static RAM and 
>> either the upper or lower 32 K of the 64K
>> Dynamic RAM in the lower.
>> 
>> The 32K segment where the ROMs normally reside
>> could also have static RAM in it.
>> 
>> It should be possible to run a second copy of
>> BASIC in the other 32K 
>> with an interrupt or other means to switch
>> between them.
>> 
>> -John
>> wb8tyw at qsl.net
>> Personal Opinion Only
>
>We used to do this very thing.
>Load a program into the low 32k,
>under program control switch pages
>and run an identical program (with a
>screen color to identify it) while
>it switched back & forth between
>32k pages (on the fly). {whew!}
>
>Another ttl scheme allowed another
>64k piggybacked dram that allowed
>4 (four) pages of 32k in the low area.
>You could run 4 different BASIC programs
>on the fly while switching 32k pages.
>I did this one too.
>
>Paul T Barton
>
>
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