This is a patch against screen-3.7.2.  It allows BRLTTY to have access
to the text (and attributes) that actually appears on the normal terminal 
when "screen" is running.  BRLTTY grabs the window image from internal 
"screen"'s structure using an IPC shared memory segment.

To use this, you must apply the patch to the "screen" source tree, run the 
configure script, run 'make' and execute "screen".  You also have to configure
the makefile for BRLTTY for IPCSHM (not for VCSA), comment out
"SCR_O = scr_linux.o", uncomment "SCR_O = scr_shm.o", and remake BRLTTY.

Note that this part is alpha and experimental.

The "screen" package can be found at:
ftp://prep.ai.mit.edu/pub/gnu/

The purpose of all this is to make BRLTTY usable on any generic UNIX
platform (other than just Linux).  As IPC may not be available on all UNIX,
we should plan similar image grabbing from "screen" using pipes or fifos.
Maybe some day....

Please do not hesitate to send comments, code, remarks, etc !!

