[Coco] Just another peek...

[Bill Pierce]

Dave, Not owning an FPGA (or SD card reader), so my knowledge would VERY limited to what I know of how a standard system works, but I think enlarging the "boot track" would involve modifying DECB... more than modifying OS9 (almost).
The DOS cmd loads the entire contents of track 34 (18 sectors) to $2600 then executes it. So the limit is in the DOS cmd.

Also, enlarging the kernel, would entail modifying all the various locations of modules (and addresses pointing to them) as that would move everything else up in memory as well. Then you run into the whole "crossing 256 byte & 8k boundries" thing.

Of course, making it single pass would involve a whole new boot techniqe as the kernel's first job is locating the rest of the bootfile (OS9Boot) and loading it into memory. Yes, it could probably be done, but it would take heavy modification to the kernel files (rel, boot, krn). Brett Gordon was working on something similar with his CocoBoot, you may want to look into that.

One thought; though I have no clue how the FPGA & SD are set up and how you are currently booting; would be to make a "standard" boot disk which contain nothing but the kernel. Then once it loads, it looks to the larger partition for the OS9Boot. This way RSDOS sees a standard sized disk and boot track...

I assume the whole problem though, lies in getting the SD card routines that load the boot, into the kernel and staying the porper size (18 sectors). That's beyond my knowledge.

As I said, I have no idea how FPGA boots OS9 as I don't own one (yet), so it's hard to say how such a thing would be done.

 

 


Bill Pierce
"Charlie stole the handle, and the train it won't stop going, no way to slow down!" - Ian Anderson - Jethro Tull

 

My Music from the Tandy/Radio Shack Color Computer 2 & 3
https://sites.google.com/site/dabarnstudio/
Co-Contributor, Co-Editor for CocoPedia
http://www.cocopedia.com/wiki/index.php/Main_Page
Global Moderator for TRS-80/Tandy Color Computer Forums
http://www.tandycoco.com/forum/

E-Mail: ooogalapasooo at aol.com


 

 

-----Original Message-----
From: Dave Philipsen <dave at davebiz.com>
To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
Sent: Fri, Oct 9, 2015 5:02 pm
Subject: Re: [Coco] Just another peek...


I have already contacted one person who subscribes to this list looking 
for
help in developing a stand-alone boot into NitrOS9 but have not yet 
received a
reply from him.  If anyone has some experience with this and 
would like to help
it would be much appreciated.  Basically what is 
involved is the modification
of the Boot module and perhaps re-location 
and re-sizing of the boot track to
the SD card.  In fact, as I see it 
there's no reason why we couldn't change the
two-stage boot process into 
a single-stage process and boot the entire NitrOS9
system in one fell 
swoop!


Dave Philipsen


On 2015-10-09 13:27, Michael Brant
wrote:
> I am also interested in knowing more about the SD card access as i 
>
would
> want a stand alone setup.
> On Oct 9, 2015 2:24 PM, "Barry Nelson"
<Barry.Nelson at amobiledevice.com>
> wrote:
> 
>> I would want one of these, but I
do not want to have to use an 
>> external
>> DriveWire server. Any updates on
how the SD card access is going?
>> 
>> 
>> 
>> >    Dave Philipsen dave at
davebiz.com
>> 
>> >    Fri Oct 9 10:51:34 EDT 2015
>> 
>> 
>> 
>> >    It works
just like the other video modes on the CoCo 3. The video
>> memory is part of
the 512k memory map. In this case about 288,000 
>> bytes of
>> memory are
used.
>> 
>> 
>> 
>> >    Dave Philipsen
>> 
>> 
>> 
>> Ø  On Oct 9, 2015, at
1:45 AM, Brett Gordon <beretta42 at gmail.com>
>> wrote:
>> 
>> >    >
>> 
>> Ø 
That's awesome Dave!  So where exactly is this video memory coming 
>> from?
>>

>> Ø  ahhh.. i really want one of these now...
>> 
>> >    >
>> 
>> Ø  --
>>

>> Ø  Coco mailing list
>> 
>> Ø  Coco at maltedmedia.com
>> 
>> Ø 
https://pairlist5.pair.net/mailman/listinfo/coco
>> 
>> 
>> --
>> Coco mailing
list
>> Coco at maltedmedia.com
>>
https://pairlist5.pair.net/mailman/listinfo/coco
>> 

-- 
Coco mailing
list
Coco at maltedmedia.com
https://pairlist5.pair.net/mailman/listinfo/coco