Xref: utzoo comp.os.os9:420 comp.sys.m6809:1043
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!sharkey!aucis!easton
From: easton@aucis.UUCP (Jeff Easton)
Newsgroups: comp.os.os9,comp.sys.m6809
Subject: RE: Adapting coco OS9 to other systems
Keywords: OS9, coco III, uniboard
Message-ID: <386@aucis.UUCP>
Date: 24 Mar 89 16:49:38 GMT
Organization: Andrews University, Berrien Springs, MI
Lines: 61

Here is a summary of the responses I got from my earlier posting about
porting OS9 from the coco III to other machines.
 
> from tim hogard                   Mailed March 20, 1989 at 11:26 pm
>
> To run os9/2 you will need hardware to map memory addresses from the 64K
> limit to the larger memory address space.
> Your problem will be to write a disk driver if you can get the os9 kernal
> moved.  I would start with a os9 level I and I would try to get the
> terminal/screen drivers written first, (you can test them out when flex is
> running) and then try to get the disk code to work.
> The coco 3 has a unique memory management chip so you will have to rewrite
> part of the level II kernal if you want level II.
> -tim
 
 
>> Dru Nelson                    Mailed March 13, 1989 at 9:03 pm
>>
>> I don't think so.  You will sort of be better off by taking Level I
>> and adding the Level II calls to it.  The coco III has the memory
>> management and the different video.  If you can hardware hack a memory
>> management unit, it shouldn't be hard to go the Level II route.  The
>> speed of your machine may also be a little, very little, important.
>> Making a ROM for the DRC should be easy with os9's module format.
>> Good luck fellow 6809'er.  If you have any problems, questions, I will
>> try to help.  It's my favorite chip.
----------------------------^
Mine too!
 
 
Okay, level 2 is out.  I could use it later after I build that 2 Meg
bank switching RAM disk I'm thinking about :>
 
Has anyone actually ported the OS9 from coco's to other machines?  Do I
need to buy a coco III just to reassemble the drivers for my uniboard SBC?
Is there enough technical descriptions of the drivers (source code 
hopefully) in the documentation that comes with the package?  Is it a
seperate item you have to buy?
 
Here's my guess at a scenario for porting it.
 
	1> Buy the OS9 level I & the assembler package
	2> Rewrite the 6551 ACIA drivers for the deluxe RS232 pak
	    for my 6551 at a different address.  sounds easy
	3> Rewrite the disk drivers for my WD 1793 disk controller
	    what chip does the coco use? a WD 17xx I think
	4> Write a boot strap loader for OS9
	5> At this point I should be able to boot OS9 with a 
	    terminal connected to my serial port.  I then
	    can write the drivers for my video (MC6845 based) and
	    keyboard (7 bit ASCII w/strobe).
 
Does OS9 require a timer for switching processes?  I have a 6522 VIA
with 2 8 bit timers.  Is this sufficent?
 
 
	-Jeff Easton
	Zenith Data Systems
 
Disclaimer:  All standard disclaimers apply.