HFS Incompatibility

[The Mangler <dayen@sfsu.edu>]

I wanted to exchange files with a friend that uses a PC.  When I
formatted a disk as MS-DOS on my GS using MS-DOS utilities, his
computer didn't recognize it, and when he reformatted the disk to MS-DOS
on his PC, my computer didn't recognize it.  What is going on?

Also, I formatted another disk into a Mac format on my GS but it showed up
on a PowerPC as a disk with no storage space available.  So, I reformatted
the disk again into a Mac format on a PowerPC this time, and it worked
fine on both machines.

The question is, why?

Daniel