[Coco] Bubble Memory

Bruce W. Calkins brucewcalkins at charter.net
Tue Aug 15 14:01:07 EDT 2017


The CoCo 3s GIME can map any 8k block from up to 2 megs of memory 
anywhere in the 6809s 64k address space.  The CoCo 1 & 2s SAM was pretty 
much limited to 32k blocks upper and lower.  OS-9 level 1, Release 2 was 
a little better than Color Basics ability to handle that, but without 
better hardware, that 32k limit does strangle things a bit.

I have the PBJ 256k Banker and OS-9 needs a patch just to boot. To date 
no one seems to have come up with the patch for NitrOS9.

Bruce W.



On 08/15/2017 11:12 AM, Brett Gordon wrote:
> that limit is done and gone no?  Tormod's spinx card now can map near 64k
> in and out.  I assume it would be trivial now-a-days to add more granular
> banking if one desired, or a crap ton of banked memory.
>
> Actually putting any such scheme to use software-wise would be probably
> more work than the hardware involved.
>
> On Aug 15, 2017 8:31 AM, "Bruce W. Calkins" <brucewcalkins at charter.net>
> wrote:
>> One of the limits to the CoCo 1 & 2 memory expansion was the inability to
> shift small-to-medium sized blocks in and out of the memory map.  Basically
> it was limited to 32k mapping blocks.  This applied to the PBJ 128k & 256k
> expansions too.  That said; RAM Disks really did speed up many processes.
>> Bruce W.



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