[Coco] 1mb and 2mb memory upgrades

[tonym]

When under DECB, did the 1MB and 2MB boards at least function as if they were a 512K upgrade?

Tony


---- Original Message ----
From: "Bill Pierce via Coco" <coco at maltedmedia.com>
Sent: 3/13/2015 2:42:10 PM
To: coco at maltedmedia.com
Subject: Re: [Coco] 1mb and 2mb memory upgrades



Brian, exactly :-)
Paul Barton's last board was up to 64 meg IIRC.
Here's the link to his old site (or at least part of it)
 http://www.reocities.com/idezilla/CoCoZilla/thumnail.html

The trick is all in the DAT board as it makes the memory available to the system.

Keep in mind, this is "available" memory... That doesn't mean anything was ever programmed to use it as no one (that I know of) ever bought enough of the boards to justify writing software for it. I think Robert Gault has one of Paul's 8-meg boards and is the only person I know of with one.
With that said, even the 1 & 2 meg upgrades have never been used for anything in DECB other than maybe a ramdisk.
NitrOS9 will automatically use the 1 & 2 megs for more 64k workspaces, graphics, get/put buffers, and windows. Any more than 2 meg and OS9 would have to be slightly modified again, but no big deal, just an extended memory map and a few bytes changed in IOMan. Still 100% compatability :-)
To use this memory in DECB, the roms would have to be completely re-written losing all compatability with old software....  and may be with some rom mods, extra graphics pages.
Chalk another one up to the modularity of OS9 as it lost no compatability, only gaining in versitality :-)
 

Bill Pierce
"Today is a good day... I woke up" - Ritchie Havens
 

My Music from the Tandy/Radio Shack Color Computer 2 & 3
https://sites.google.com/site/dabarnstudio/
Co-Contributor, Co-Editor for CocoPedia
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E-Mail: ooogalapasooo at aol.com


 
 
-----Original Message-----
From: Brian Blake <random.rodder at gmail.com>
To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
Sent: Fri, Mar 13, 2015 1:47 pm
Subject: Re: [Coco] 1mb and 2mb memory upgrades


On 3/13/2015 1:46 PM, Luis Antoniosi (CoCoDemus) wrote:
> 2MB is the maximum you
can use in the MMU registers: 256 x 8K
>
> Luis Felipe Antoniosi
>

Someone
forgot to tell that to Paul Barton....



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