[Coco] New Improved Nitros9 Booting

Sun Feb 12 23:09:10 EST 2012

On Sunday, February 12, 2012 10:53:59 PM Brett Gordon did opine:

> Thanks for the input Gene, Robert.  I was under a false impression
> that near noone used more than 1 sector per cluster.  I'll have to
> take a look at my CF that came with SuperIDE, and see just what my
> sectors-per-cluster is set to.  Do LSN's then become cluster
> addresses?  or is the cluster setting simply for the allocation
> bitmap?  I do remember manually wandering through the root directory
> file, and wondering why 8 sectors where in the File Descriptor's
> Segment Count, but the file was only 4 sectors in length.

Its just for the bitmap, Brett.  The problem comes in at about 134 
megabytes, when the drive gets bigger than that, we run out of bitmap 
space, which is limited to 65535 bytes overall.  Then since at a cluster of 
one, each byte represents 8 sectors, so the map is full at 134,215,680 
decimal bytes worth of hard drive.  The cluster size can only be raised by 
powers of 2, so the sequence then is 2,4,8,16,32 etc. I think there is a 
higher quitting point too since the LSN addressing scheme is only 24 bits, 
so we're out of room again at either a bit over 4 gigs, or a bit over 
2gigs, depending on whether or not the math that does the LSN twiddling is 
signed or unsigned.  At this late date I don't recall, but would assume it 
is signed, in which case we're done at a bit above 2gigs.  Drives even that 
small are rapidly becoming un-obtainium. :(  So the day may come when we 
have a 2gig partition on a 2 or 4 terrabyte drive & that is all the drive 
we can use.  But when that day comes, Mark is going to have to get busy & 
build us a SATA disk controller.  Boggles the mind, doesn't it Mark? 

> Brett Gordon
> 
> On Sun, Feb 12, 2012 at 10:29 PM, gene heskett <gheskett at wdtv.com> wrote:
> > On Sunday, February 12, 2012 10:21:17 PM Brett Gordon did opine:
> >> Maybe cobbler can be changed a bit to add a command line switch to
> >> ignore the track 34 install of the REL/BOOT/KRN combo.  It won't find
> >> them anymore in memory with a bootup from CoCoBoot.  Track 34 stuff
> >> should still be in there for the people wishing to keep support for
> >> the old-school booting.
> >> 
> >> That's quite neat that cobbler reads the module layout from memory.
> >> Good Stuff.  I'm finding it hard to find documentation on some of the
> >> standard os9 commands like cobbler, os9gen an the such.  I would hate
> >> to have to read (and understand) all the source!
> >> 
> >> I should point out that the existing incarnation of the Nitros9 setup
> >> wizard only works with RBF images utilizing 1 sector cluster sizes.
> >> From what I understand it is very uncommon to have anything more than
> >> this.
> > 
> > No, if you have a hard drive, it is likely more than 1.  I have two
> > HD's on mine, one is half for hdb-dos so its running the first half a
> > gig a a cluster size of 4, and the other, otherwise identical drive
> > is a gig, running at a cluster size of 16.  They work fine AFTER I
> > undid Kevins 1988? "Christmas Present" which removed that capability
> > from rbf.mn.
> > 
> > That fixin has been in nitros9 for quite a spell now.  I put it back
> > in when I did the original conversion of rbf.mn to make use of the
> > 6309 commands, and then Boisy put in conditional assembly stuff so it
> > builds for either cpu, and has for at least a decade now IIRC.
> > 
> >> The source for the wizard is under the "contrib" directory as
> >> "os9l2.fs" in the SVN at sourceforge if anyone wants to see.
> >> 
> >> I'll shortly be working on Nitros9 Level 1 booting, but I might take
> >> a break to mess around with Aaron's Virtual Serial Port protocols in
> >> DriveWire 4.
> > 
> > Those are fun.  ;-)
> > 
> >> Brett Gordon
> >> 
> >> >Boisy G. Pitre boisy at tee-boy.com
> >> >Sun Feb 12 20:24:26 EST 2012
> >> >
> >> >Robert,
> >> >
> >> >Cobbler also writes REL/BOOT/KRN to track 34. With the new boot
> >> >method,
> >> >
> >> >>cobbler will probably fail.
> >> >
> >> >I envision a version of NitrOS-9 that is supported exclusively by
> >> >CoCoBoot. >This version would have no cobbler and no os9gen. What
> >> >version that will be, I >haven't decided.
> >> >
> >> >Best Regards,
> >> >Boisy G. Pitre
> >> >
> >> >>On Feb 12, 2012, at 7:20 PM, Robert Gault wrote:
> >> >> Cobbler does more than set a pointer to OS9Boot in LSN0. Cobbler
> >> >> takes >>the modules as they exist in memory and creates a new
> >> >> OS9Boot file. This >>means you can change descriptors in memory
> >> >> with programs like dmode, >>tmode, wmode, and xmode and after
> >> >> using cobbler the changes will be >>"permanent".
> >> 
> >> --
> >> Coco mailing list
> >> Coco at maltedmedia.com
> >> http://five.pairlist.net/mailman/listinfo/coco
> > 
> > Cheers, Gene
> > --
> > "There are four boxes to be used in defense of liberty:
> >  soap, ballot, jury, and ammo. Please use in that order."
> > -Ed Howdershelt (Author)
> > My web page: <http://coyoteden.dyndns-free.com:85/gene>
> > "When anyone says `theoretically,' they really mean `not really.'"
> >  -- David Parnas
> > 
> > --
> > Coco mailing list
> > Coco at maltedmedia.com
> > http://five.pairlist.net/mailman/listinfo/coco

Cheers, Gene
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
My web page: <http://coyoteden.dyndns-free.com:85/gene>
We cannot do everything at once, but we can do something at once.
		-- Calvin Coolidge