[Coco] CUBIX on the CoCo?

[jdaggett at gate.net]

On 30 Oct 2005 at 6:41, Dave Dunfield wrote:

To:             	CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
From:           	Dave Dunfield <dave04a at dunfield.com>
Subject:        	Re: [Coco] CUBIX on the CoCo?
Date sent:      	Sun, 30 Oct 2005 06:41:50 -0500
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> Another possible area of concern is that CUBIX was designed to be
> installed in ROM, and therefore does not provide for a "boot sector"
> on it's floppy image. It starts off with the directory and allocation
> map and does not have any "spare room" for bootstrap. I am not 
> familier with how the CoCo boots, however it it is necessary for it to
> have a bootstrap at the start of the disk, the easy solution is to
> logically offset the CUBIX area by enough sectors to accomodate the
> bootstrap.

ROM is no problem. The Coco 3 can have up to 32K less 256 bytes of ROM 
mapped from $8000 to $FF00. What one can do is map the ROM at $C000 and 
then a RSBASIC loader then can copy the ROM code to ram at $E000. 
Somewhat similar to what Disk Extended Color Basic (DECB) does. The Coco3 
copies the rom into ram and executes everything in RAM. Then execution could 
jump to it or an added wrapper program could interface with the hardware and 
OS to use the 512K of RAM that the Coco3 has. 

As long as the OS can maintain a size of 8K then it will fit in any block of RAM 
that is available and the MMU then can map that block in. 

james