[Coco] Re: OS-9 as Replacement for DECB.

[John R. Hogerhuis]

On Thu, 2005-09-01 at 13:35 -0500, Boisy G. Pitre wrote:

> B. Hardware solution - What would be necessary is a small board with  
> flash and appropriate logic to implement a "switching register".   

Haven't been following this real close, but it seems to me the Coco
already has a MMU. So the hardware is there to have multiple "virtual
cocos" on the same machine.

Has anyone ever tried reserving 8 8K chunks and copied in a 64K coco
image and run it under OS-9? 

The hard part would be sharing hardware. But if one were to give up
multi-tasking (i.e. once a virtual machine is switched away from it
stops running), it would be mostly a matter of having some code to
re-init hardware after a switch.

Anyway, it would be pretty cool to be able to run ECB BASIC programs
without having to reboot. Running Coco 1 & 2 ML games is in the margin
of possibility, but probably too hard to do Coco 3 programs since they
would tend to want to "own" the MMU and probably a good portion if not
all of the memory.

Perhaps on a 1Meg coco though... one could devote the lower 512K to the
standard Coco 3 programs. The upper 512K for OS-9.

Probably with compression, the original basic roms and a minimal os-9
boot kernel could be crammed into the existing ROM space. I think one
should still count on some type of external storage though... could do
drivewire if really wanted to avoid using the cart port.

-- John.