[Coco] Re: NitrOS-9 V03.02.01 Release

[Rodney V Hamilton]

In article <20040520.230456.1004.1.elderpav at juno.com>, 
elderpav at juno.com says...
>
>> The version of DSKINI.EXE probably is OK. There have been issues in the 
>> past using 5 1/4" drives that require BIOS adjustments. Since I use a 
>> 3.5" drive on both PC and Coco, I've not paid too much attention to BIOS 
>> settings. Do a Google newsgroup search for this.
>> 
>> My suggestion would be to get a 3.5" drive and install it on the Coco.
>> 
>> By the way, what do you see on your 5.25' drive when you boot into OS-9 
>> with a different system disk attempt to read the problem disk?

The June 8 2003 DSKINI.EXE is indeed the latest version.  The main change
from previous versions is that it formats ALL the tracks even if the disk
image file is less than the full size.  If your 5.25-inch drive is a 360K
unit, there may be a problem with DSKINI - a note on Jeff Vavasour's site
suggests telling the BIOS it is a 720K unit instead.  The 3.5-inch drive
should work fine since no track-stepping tricks are needed.

>I forgot to mention that I already have a 3 1/2" drive installed on the
>Coco. So why am I using 5 1/4" disks? Because I haven't had any success
>using DSKINI to transfer the images to a 3 1/2" disk, either. Even if I
>do succeed in executing the command without getting a write error, the
>resulting disk is unreadable on the Coco. I get "Error 249 - Wrong Type"

Fred, have you looked at LSN0?  The NitrOS-9 DD80 image has the DD.FMT
byte at offset $0010 set to $07 (96tpi DSDD) but your drive descriptor
for the 3.5 drive is probably still set to DNS=1 (48tpi DSDD).  To fix
it, try setting the DNS value to 3 (eg: DMODE /D1 DNS=3) and see if you
can now read the 3.5 disk.  Alternately, you can patch LSN0 on the 3.5
disk and change the DD.FMT value from $07 to $03 - this is what I do on
my disks so I can read 3.5-inch 720K disks with the default /D1.

If I change DD.FMT to $02, I can read the 80tk DSDD image in the JV/JC
emulators, and even boot from it with my double-sided boot patch.

>When I boot OS-9 using another boot disk and then analyze the problem
>disk, I can DIR the root directory and the DEFS directory, but I get a
>seek error when I try DIR-ing the SYS directory. When I tried DIR-ing the
>CMDS directory, it gave me a 'no permission' error, and when I checked
>the attributes, CMDS is listed as a file, not a directory! Obviously the
>disk is garbled, due to a faulty DSKINI operation I imagine.
>
>Fred Provoncha

Again, check the LSN0 settings - it's almost certainly a density setting
mismatch between the disk and the descriptor.

I hope this helps.

Rodney Hamilton