[Coco] Re: Re: Bellingham User Group Stuff

[Rodney V Hamilton]

In article <024101c3eabd$521a9c20$87026742 at pentium>, 
bcalkins at disaster-relief.net says...
>
>Well, I think I understand what you are saying.  However I don't know how to
>get there, yet.  Is there a tutor in the house?
>
>Bruce W.
>
>P.S. I have also mounted them in the JV Emulator, with the same results.
>(Although I did have a go-a-round with Windoze's hidden extensions!)
>
>
>
>> I suspect that bit 1 of byte $10 in LSN0 is not set. It should be,
>> indicating to the driver that the disk is formatted as a 96tpi disk.
>>
>> Look at offset $10 of LSN0 of the disk image.  It should be $03, not
>> $02.
>>
>> Boisy
>>
>> On Feb 3, 2004, at 4:10 PM, Bruce Calkins wrote:
>>
>> > O.K.?  I've downloaded these DSK images, changed the extension to dot
>> > DSK,
>> > Written them to 720k floppy disk with John Collyer's upgraded DSKINI,
>> > and
>> > tried to read them on my CoCo under OS-9.
>> >
>> > Result?  249 error - wrong type
>> >
>> > What's wrong?
>> >
>> > Bruce W.

Bruce, Poisy, I downloaded several of the "bug" images and scanned
through them with a hex editor.  Their LSN0 byte $10's bit.1 *IS*
set - the byte is $07 in all cases.  HOWEVER, that's not the problem!

It looks like *ALL BYTES* that had the high bit set are scrambled
in strange ways.  For example, the disks were named as "PD Library"
where you'd expect the 'y' to be $F9 ('y'+$80) but it's not.  And
the allocation table is mostly set to $C2 instead of $FF.  All the
directories are unreadable also.  The '..'  and '.' dir entries
have their last byte set to $C6 instead of $AE.  All the filenames
are similarly messed up on their last characters.  The $87CD module
ID words are all replaced by $E1D5, and so on through the entire
disk image.  It looks like the bytes below $80 are OK since I could
still read the embedded text strings and LSN0 bytes below $80.
I think all 9 disks need to be re-read and re-uploaded.

Rodney