[Coco] Create Nitros9 DSK on SDC

[Robert Gault]

I have found a method for creating large images ie. vhd type images on the SDC 
after modifying
a program sent to me by Darren.
In essence, a new disk is created via SDC-DOS by indicating the desired name and 
the number
of sectors on the image. The Basic program writes to the "last sector" on the 
disk, thus creating it.
Using the latest NitrOS-9 sdc release, with dmode set for sid=1, sct=12, t0s=12, and
cyl="whatever" needed to get the total number of required sectors.
You now have a new OS-9 disk that needs formatting. So I used Format to create 
the actual disk
structure but unfortunately the image contains lots of junk as Format does not 
erase the sectors.
So, I erased sectors $264-276 using ded and then ran Cobbler. The OS9Boot file 
was created
but I kept getting 207 errors, not enough memory on my 512k Coco3. So no "T34".
So with the NitrOS-9 release disk in SDC drive0 and the new disk in drive1, I 
ran a Basic program
to transfer track 34 from the bootable disk to the new one.
I then booted from the release disk and ran   dsave -s24 /SD1 ! shell -p   to 
transfer all the directories
and files to the new disk.
The new disk which has $5A000 sectors booted into NitrOS-9 v3.3.0 via the DOS 
command. This
is the same sized disk as the .vhd used with MESS and VCC but without the Basic 
partition. I can
used a full .vhd drive with both OS-9 and Basic partitions by placing a version 
of HDBDOS on the
SDC card and starting that DOS with the RUN at 6 command with HDBDOS in memory slot 6.

Create a new disk
10 PRINT "NEW IMAGE FILE NAME":INPUT N$
20 DRIVE 1,N$,NEW
30 INPUT "SIZE (SECTORS)";SS
40 ST=SS/&H10000:SU=INT(ST):SV=(ST-SU)*&H100:SX=SS-SU*&H10000-SV*&H100
50 POKE &HFF40,&H43
60 POKE&HFF49,SU
70 POKE&HFF4A,SV
80 POKE&HFF4B,SX
90 POKE &HFF48,&HA1
100 PRINT "ALLOCATING SECTORS..."
110 S=PEEK(&HFF48):IF S=1 THEN 110
120 IF S>127 THEN PRINT "I/O ERROR!"
130 POKE &HFF48,&HD0
140 POKE &HFF40,0

Transfer track 34 so DOS works
10 CLEAR 1000
20 DIM A$(128),B$(128)
30 FOR S=1TO18
40 DSKI$ 0,34,S,A$,B$:DSKO$ 1,34,S,A$,B$
50 NEXT

Robert

Jeff Teunissen wrote:
> That's actually the problem, Bill. As far as I can tell, you can't
> automatically extend a disk image with a CoCoSDC no matter how it's
> made. You can format a 35-track disk image with the data for a hard
> drive, but it's never going to be able to hold more than 157.5
> kilobytes -- you'll start getting errors as soon as you try to seek
> past the end of the disk.
>
> Regarding NitrOS-9 and SDF disks, I think it should be entirely
> transparent unless you try using the LBA mode (llcocosdc), which
> probably does in fact bypass the SDF stuff. I think you SHOULD be able
> to use, and format, SDF disks if you only access them using the
> regular "rb1773" driver.
>
> ><snip>