[Coco] error 249

Robert Gault robert.gault at att.net
Sat Mar 18 15:33:57 EDT 2017

Bill wrote:
> Actually I wasn't USING them, just making sure the disk was still good. and when I rebooted with the DISK version of NitrOS9, I saw that it WAS good.
> The 249 error occurs with ALL of the nos96809l2v030300coco3_dw.dsk (I re-downloaded it several times) I boot up with using DriveWire. When I boot with my disk-bases NitrOS9, it doesn't happen.
> I'm confused!!!


If I understand the above, the answer seems simple but you still need to find what is wrong.
If you boot from your Coco floppy drive and can read Coco floppies correctly but get a 249 error 
when booting from a DW4 disk, then there must be a problem with the rb1773, rbf, or the D# 
descriptors on the DW4 disk.
The idents for rbf and rb1773 on the nos96809l2v030300coco3_dw.dsk I'm using are

size $5A9
crc  $A4EB50

size $12EE
crc  $245E32

Regards the many comments about the descriptors, I am using MF2DD, 135 TPI, 80 track, 3.5" disks in 
my drive#1. I can format it for single or double sides, 35, 40, or 80 tracks per side but TYP=$21.

When format starts, it shows TPI=135. If you see something else, use dmode to change typ.


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