======================================================================
Introduction
======================================================================

First off, no guarentees for you.  This works for me, and if it
doesn't work for you, email me, and I'll try to help.

Second, don't expect things to make sense if you try to use
X or anything else that uses graphics.  I don't usually run
X, but I'm going to install it soon just to play with this.
I do use this regularly with dosemu, and I can use graphics in dosemu
just fine.  And I've had this work with vgalib too, but I personally
still don't know about X windows.  I've heard rumors that if you
run X on the color screen, it blanks your mono monitor...

Third, you can still get yourself into trouble with things that use
text only, like dosemu.  If you run dosemu with console i/o enabled,
and you swap it to the other monitor, be prepared to have to hit that
reset button to unlock your machine.

The original dual-monitor patches were written by Tuomas Lukka,
and then modified by Cory West to work in later kernel versions.
I have rewritten almost all of the support for the linux 0.99.pl10 
kernel.  These still do not do auto-detection of the mono card
at the moment, but I hope that can come soon.  Some of the changes
are to make this simpler to add in later.

Previous to my inheriting the dual-monitor patches, you were required
to statically allocate which vc's would display on which monitor
when you compiled the kernel.  I have added support so that
you can put any vc on either monitor at run time.

--- quote Cory:

  To test out your monitor setup before bothering with this
patch, bring up DOS on you two monitor system.  It should come up with
one monitor active (SVGA).  When you type 'mode mono' the SVGA monitor
should freeze and the MDA-Herc monitor should become active.  Issuing
'mode co80' should return you to the SVGA monitor.  If you can switch
between displays in this fashion, these patches should work for you.
Otherwise, you'll have to figure out the setup problems on your own.

--- end quote

======================================================================
Installing
======================================================================

To get this into your kernel:

  cd /usr/src
  patch < patchfile

things in the source you may wish to play with:

  kernel/chr_drv/console.c:
    MONO_CONSOLE
      this chooses which console first appears on the mono monitor.

  kernel/chr_drv/keyboard.c:
    RIGHT_ADAPTER
    LEFT_ADAPTER
      these choose which video adapter card is on the left, and which
      in on the right.  change as you please...

======================================================================
Usage
======================================================================

The right-alt key with a function key selects a vc to appear
on the color card, while the left-alt key with function key
selects the vc to put on the mono screen.  Which key selects
which monitor is selectable at compile time with the RIGHT_ADAPTER
and LEFT_ADAPTER constants in kernel/chr_drv/keyboard.c

In dosemu, the right-alt key is not interpreted to mean switch
switch consoles.  You will need to use the left-alt key to change
to a different console, then the right-alt should work.

The way the kernel determines which monitor is intended is actually
quite lame.  The modern keymaps have support for 24 consoles, using
both alt keys, so now I just map consoles 13 to 24 as 1 to 12 but
on the other monitor.  Which set is on which monitor is determined
by the RIGHT_ADAPTER and LEFT_ADAPTER that is in keyboard.c.

======================================================================
Support
======================================================================

Please feel free to mail me with all comments...

jeff grills
jefftep@cs.utexas.edu
