shared read/write data segment under unix/C

[Karl Danz]

[]
	We needed shared memory support in 4.2 and after
some investigation realized that Berkeley had started to
implement it.  (Check out "man page" for mmap system call
in the System Manual.)  We put in mods to support shared
memory using some of the "ifdef'd out" code in the 4.2
distribution as a starting point.

	Our needs were small enough (less than 100K) that
we simply set up a fixed buffer in kernel storage to which
we point the page table entries of processes requesting
use of the shared memory... crude, but it works for us.
If anyone is interested, I can send our mods.

				Karl Danz
				Cygnet Systems