Shared memory is an other method for BRLTTY to get the content of the
screen. For this methods you need to parts: 

1. BRLTTY needs to receive the information. Tis is done by scr_shm.cc.
2. An other program needs to send the screen image. 

Such modifications have been made to the screen package. The original
purpose of screen was to run different "screens" on a single terminal. It
also supports things like copy and paste etc. Scrren runs on lots of
terminals, especialy in XTERM. This is important, because it runs under
X-Windows. X-Windows is part of most unixes.

So - theoretically - by applying the modifications to the screen package and
compiling brltty and screen, you should be able to use brltty on something
else but linux.


Instructions

1. Set the screen driver in the Makefile to scr_shm (inted of scr_linux).
   You can do this by just adding and removing comment signs (#)

2. Run 

   make all

   to build brltty

3. Get the screen sourcecode from 

   ftp://ftp.uni-erlangen.de/pub/utilities/screen/screen-4.0.1.tar.gz

   It's important, that you get THIS release (4.0.1), because the patch
   doesn't fit on anything else without extra work.

4. Unpack the source 

   tar zxfv screen-4.0.1.tar.gz

   and change to the source directory

   cd screen-4.0.1

5. Apply the patch: 

   cat <brlttydir>/Patches/screen-4.0.1.patch | patch

6. Build screen:

   To build screen type:

   ./configure
   make


7. Now you can run brltty and then screen


Notes:
* Cursor routing and brltty's copy/paste don't work, because feeding
  something into the keyboard buffer is not yet possible. Screen has it's own
  keyboard feeding mechanism, but there's no interface yet.
* the status messages of screen don't appear on the braille display.
* I tried the patch on SuSE Linux 7.3, in an XTERM window in KDE. I didn't
  have opportunity to test in on any other unix system.
* The patch for screen-4.0.1 is based on that for version 3.7.2. The update
  was necessary, because screen-3.7.2 doesn't compile any more with modern
  c-libraries.


Contact: rudolf.weeber@gmx.de
