Re: Mac Recognizing a ProDos volume

[shack@deimos.frii.com (Randy Shackelford)]

[Article reformatted to be followup-friendly. Man I wish people would put 
new text below quoted text]

In article <34350509.1B8A@s2.sonnet.com>,
Daryl Morgan  <dcm@s2.sonnet.com> wrote:

>>Never heard that one, but I do know that PC Exchange will not recognize
>>ProDOS partitions unless they are strictly less than 32 MB.  (I don't
>>recall exactly how I partitioned my hard drive years ago, but I think
>>it was with ADU, and it ended up with partitions that were exactly 32
>>MB.  I had to shrink these by a block before I could get PC Exchange to
>>mount them.)

>How do you shrink the partitions without erasing the drive?

There's a two byte value called total_blocks in the volume directory header,
and it denotes how many blocks are on a volume. A little judicious block
editing can reduce the number of blocks on the volume. You'd want to stay
within the same multiple of 4096 blocks though, or else you'd change the
number of bit map blocks necessary for the volume.
-- 
Randy Shackelford                                 
shack@frii.com