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NitrOS-9 on Dragon 32 (unmodded)

Posted: Thu Mar 13, 2014 12:09 am
by tormod
NitrOS-9 on Dragon 32
nitros32.jpg (67.14 KiB) Viewed 2195 times
Unveiled as the special surprise at tonight's meeting, here is NitrOS-9 running on my Dragon 32 :)

Not awful amounts of memory left for applications though, mfree reports 1+27 pages.

(The reason the screen is b/w is because my S-video output is still WIP.)

Re: NitrOS-9 on Dragon 32 (unmodded)

Posted: Thu Mar 13, 2014 9:20 am
by sixxie
Hah, brilliant. So is there any useful stuff you can get done with what's left?

ISTR OS-9 mostly putting its stuff at the top of RAM, so that must have taken some juggling.

Re: NitrOS-9 on Dragon 32 (unmodded)

Posted: Thu Mar 13, 2014 8:59 pm
by tormod
Well, since I am involved in NitrOS-9 maintenance/development it is already useful for me to be able to boot up on real hardware and run a few system tools, and to test DriveWire and other things that cannot be fully tested in an emulator. I can imagine some fun things like remote terminal server should be possible. But I don't know yet of any useful applications that fit. If "useful" is valid in this context :D

It should be possible to optimize NitrOS-9 to leave a bit more free space. For instance are some boot and init modules stuck in memory after booting. And of course having some of it resident on a ROM cartridge would help a lot.

In fact there was not much juggling needed, basically a one-liner change to load the boot track below 32K. It only maps memory up to the boot track anyway. I also changed the boot screen VDU location from $8000 to $0400 so that instead of watching the ROM, I can see the guts of NitrOS-9 while it is booting.

[EDIT: added disk image and updated patch]

Re: NitrOS-9 on Dragon 32 (unmodded)

Posted: Fri Mar 14, 2014 9:10 am
by KenH
Hahaha Cool :D
Also should be useful for testing the 80 column board OS9 drivers ;) Can't use an emulator for that.
I believe that using an 80 column board you can get a couple more free pages, since the VDG memory is freed.
You still won't be able to run basic09, but at least the format command should work.
And I thought memory was tight with NitrOS9 and 64K!

Re: NitrOS-9 on Dragon 32 (unmodded)

Posted: Fri Mar 14, 2014 7:48 pm
by retrocanada76
a stock dragon 32 ? It says Dragon 64 on boot screen :P

Re: NitrOS-9 on Dragon 32 (unmodded)

Posted: Sat Mar 15, 2014 10:50 am
by tormod
Yes, stock. Blame the poor NitrOS-9 hardware detection :) It is actually the coco2 build (which defines the module/driver selection), with the d64 port flag set (which defines the Dragon keyboard translation and not much else). So after applying the patch, run "make dsk PORTS=coco2".

Re: NitrOS-9 on Dragon 32 (unmodded)

Posted: Mon Mar 17, 2014 1:59 pm
by retrocanada76
This is cool but I'm afraind there isn't much ram for anything :) can you format a disk ?

The dragon 64 message is hard coded in the SysGo I guess. Need to create a specific one for dragon32.

Re: NitrOS-9 on Dragon 32 (unmodded)

Posted: Mon Mar 17, 2014 8:55 pm
by tormod
Well, the NitrOS-9 format command is 4KB of code (that is half the size of the entire HDBDOS...) and needs a 11KB data segment, so that is not the easiest of tasks.

The displayed machine name when sysgo is running comes from init.asm. I am not planning an official d32 port yet though, unless by popular demand :)