[Coco] Re: NitrOS9 on MESS?

[Nathan Woods]

Allen Huffman writes: 

> OKay, I may be coming to the party late, but ... does MESS handle 40
> track double sided disk images like the NitrOS9 release?

Not directly; by default it will interpret it as single sided.  There are 
two possibilities: 

1.  Prepend a JVC header to the disk image, to tell MESS about the geometry 
of the disk.  This information is at 
http://pw1.netcom.com/~tlindner/JVC.html 

2.  MESS has a hack by which you can change the file extension to ".os9", 
and it will figure out the geometry based on the OS9 boot sector. 

Also note that there is a bug in MESS that makes later NitrOS-9 versions 
unusable.  Disks will become corrupt after a certain amount of usage.  This 
affects both real disks images and VHD virtual hard disks.  Apparently, 
somewhere deep in the RBF module the cache structure somehow unloads to disk 
incorrectly and the disk gets corrupted. 

Robert Gault and I probably put in at least 100+ hours between us trying to 
track this one down, without any luck.  This bug affects both the 6809 and 
6309 versions of NitrOS-9, but does not affect older versions of NitrOS-9 
nor OS-9.  What I would like to see is someone isolate what specific change 
to NitrOS-9 caused this bug to manifest; that information would probably 
unlock the secret of this bug.