Re: Alternate Reality Crack

["Charlie" <charlieDOTd@verEYEzon.net>]

"sicklittlemonkey" <nick.westgate@gmail.com> wrote in message 
8931c873-9dfd-48a9-8879-1859d66a2cf8@q2g2000pre.googlegroups.com">news:8931c873-9dfd-48a9-8879-1859d66a2cf8@q2g2000pre.googlegroups.com...
On Feb 24, 7:38 am, Mike Maginnis <magin...@computist-project.net>
wrote:
>> "Michael J. Mahon" <mjma...@aol.com> wrote:
>> > Curious--where is CII+ getting this?
>>
>> Not sure. Might just be some weirdness from using Copy II Plus in an
>> emulator. My thought at this point is that the .dsk images don't work
>> because the volume numbers are wrong. I think the SuperIOB controller
>> removes most of the protection, but the volume number requirement 
>> remains.
>> I could be totally off-base though.

> Yes, it must be just the vol nums, and possibly write protection.

> CII+ must be getting it from the DOS tracks, either the boot tracks,
> or possibly (less likely I think) VTOC. Will have a look if I find
> time.

On standard DOS 3.3 disks the volume number is in the VTOC (byte 06).  I've 
often wondered why emulators don't just look at this byte for .dsk images. 
Of course a copy protected image could spoof this number making it different 
than the ones in the sector header. Also, a non-standard DOS could move the 
VTOC making it difficult for the emulator to find.  Still I think it would 
be better for an emulator to use whatever it finds in the VTOC (track 17, 
sector 0, byte 06) than simply giving it a 254 or whatever.

Charlie