[Coco] Brother Jeremy's OS-9 Level 3 (are you out there, Jeremy?)

jdaggett at gate.net jdaggett at gate.net
Thu Apr 12 21:53:11 EDT 2007

On 12 Apr 2007 at 17:48, Joel Ewy wrote:

> Actually, IIUC, what Br. Jeremy has is an unreleased upgrade to OS-9
> Level II for the CoCo 3. Traditionally, the OS-9 kernel was contained
> in a module named OS9 (or OS9P1? I'd have to check to be sure.) OS-9
> Level II, which added support for a memory management unit, was
> supplied in a module called OS9P2. Other extensions to the operating
> system could likewise be chained on the end, so an OS9P3 module could
> be added which provides yet more kernel-level system calls. This,
> presumably, would be a "Level 3". I don't know if Microware ever
> provided an OS9P3. But NitrOS-9 does have a Level 3.

I thought the original beauty of OS9 is that expansion of the kernal can be done 
with modules like OS9P3, P4,... PX.  If they don't work then you just delete the 
file and you don't have to rebuild the whole kernal. You can customize the kernal 
and if it doesn't work it was easy to revert back to what did work without 

OS9 can be compiled to work from ROM/Flash and never have to use a hard 
drive or a floppy drive. To prove this the Motorola Pagewriter 2000 uses a version 
of OS9 that was ported to the MC68328 and used 512K of Static Ram and two 4 
Megabit flash memory devices. One flash contained the whole operating system 
and some basic applications. The second flash would hold user data and user 
applications. The OS used 512K of SRAM for video and OS. While the video 
could support 640x480 resolution the actual LCD monochrome display was 
320x200. User applications could scroll horizontally and vertically through a VGA 
display memory map. 

One of the neat 3rd party apps for the Pagewriter 2000 was a hurricane tracking 
program. It actually was a full VGA graphics file with a map of the Atlantic 
hurricane region with updated postion of any active hurricane. Use to get updates 
when ever the NHS issued them. 

just a bit of history.


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