[Coco] 512K AND Beyond??? How FAR Beyond???

Robert Gault robert.gault at att.net
Wed Dec 27 09:08:30 EST 2017

Allen Huffman wrote:
> On Dec 26, 2017, at 11:23 PM, Joe Schutts via Coco <coco at maltedmedia.com> wrote:
>> Another related question. If you have a 1 or 2 Meg system, is that memory even accessible from Basic or does accessing it require OS-9 only (or NitroOS-9)???
>> Last question. Is it possible to access even more memory (higher than 2 Meg) with a CoCo 3 and if so WHY hasn't someone built (or even designed) a board and sell it here??? You listening Ed??? Just kidding...
>> Thanks Everyone...
> There was even an 8meg upgrade someone built.
> But no, stock BASIC won’t use it. Neither will OS-9. You had to have special patches for OS-9 and then it could. I do not know if anyone modified any of the BIG BASIC type programs for those upgrades, but OS-9ers made real good use of it.
> I am unaware of any software that was ever written to use it, though, Beyond OS-9, and even then, All it did was allow you to load more modules in memory at the same time, or have a larger RAM disk perhaps. Programs were still limited to fit within the 64K system area.
> Though, Bank switching and stuff could have been used to get around that. I jus don’t think anyone needed it.

You can read about the 8Meg board here http://www.geocities.ws/idezilla/CoCoZilla/8mbdet.html
Note that I wrote several test programs that can extensively test this memory. The test programs are 
on this site and they work with MESS and VCC emulators.

There are some notes at the above site where I try to explain how the memory should be used.


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