SAM Coupé to Linux Keyboard Relay

I have written several programs that allow a SAM Coupé with the Comms interface to be used as the keyboard (and mouse) for any machine running Linux with an RS232 port. These programs are:

event — the Coupé program which sends keyboard scans and mouse coordinates over the comms interface. The disk image includes both the serial comms driver and the mouse driver. These are loaded automatically when booting from this disk. The source code to ‘event.cde’ is on the disk (in SC_Assembler format), but this has no comments. You can download it (with comments!) as a text file, though.
userevent — a Linux kernel module that allows the keyboard and mouse events to be received. There is also a test program (usertype) for this kernel module.
samevent — a program that receives keyboard scans and mouse coordinates from the Coupé and then sends the appropriate events to the userevent kernel module.

Warning: the userevent module has possible security implications. If a user is given permissions for the /dev/userevent device, this is equivalent to handing the machine’s keyboard and mouse to that user. The user may be able to perform reboots, kill processes, etc. without the need to log in.

Licence

The drivers (and DOS) on the event.dsk are not my own work. They were Copyright © M.G.T. and SAMCo respectively. The Coupé programs (event.asm and event.bas) are in the public domain. The GNU/Linux programs (userevent, usertype and samevent) are distributed under the terms of the GNU General Public License (GPL).

Usage

To create the relay, perform the following (as root):

Compile userevent with the build script.
Compile samevent with ‘make’.
As root, load the userevent module by running the mknod.userevent script.
As root, run samevent, passing the input from the SAM Coupé to standard input. E.g: ‘samevent < /dev/ttyS0’ root), and load and run ‘event’ on the Coupé. It should now be possible to type text, using the Coupé as a keyboard. If your Coupé has a mouse attached, it should also be possible to use the Coupé’s mouse with GPM or X.

Pitfalls

The userevent module has security implications. Make sure that you understand the paragraph explaining these before you use it.
Currently, ESCAPE cannot be handled. However, you may be able to use Ctrl-[. A workaround for this would be to modify samevent such that the EDIT key (which currently sends KEY_RIGHTALT) sends KEY_ESC.
Certain keys are not present on the Coupé, including the grave (`), backslash (\) and hash (#) keys.
The Coupé’s keyboard does not distinguish between the left and right Shift (and Symbol-Shift) keys, so samevent can’t, either. This also applies to the two dot (period) keys.
The userevent driver does not provide support for a bell.

Changes

samevent

2005-08-07 22:09:14 BST: 1.2
   Renamed to "samevent" (was "samkbd").
   Added mouse support.
   Now using "/dev/userevent".
   Updated to the userevent-1.2 protocol.
   Added "userevent.h".

2005-08-05 19:49:28 BST: 1.1
   Made the EDIT key send KEY_RIGHTALT (instead of KEY_META).
   Made the CNTRL key send KEY_LEFTALT (instead of KEY_LEFTCTRL).
   Made the SYMBOL keys send KEY_LEFTCTRL (instead of KEY_LEFTALT).

2005-08-02 00:47:13 BST: 1.0
   Initial release.

userevent

2005-08-07 22:09:14 BST: 1.2
   Renamed to "userevent" (was "usrkbd").
   Added key repeat support.
   Added mouse support.
   Now using "/dev/userevent" (was "/dev/usrkbd").
   Added "userevent.h".

2005-08-05 19:49:28 BST: 1.1
   The build script now determines the build directory using "uname -r".

2005-08-02 00:47:13 BST: 1.0
   Initial release.

usertype

2005-08-02 22:09:14: 1.1
   Renamed to "usertype" (was "kbdtype").
   Now using "/dev/userevent".
   Updated to the userevent-1.2 protocol.
   Added "userevent.h".

2005-08-02 00:47:13: 1.0
   Initial release.  Appears to miss keys ocassionally.

event.asm

2005-08-07 22:09:14 BST: 1.2
   Renamed to "event" (was "keyb").
   Added mouse support.

2005-08-05 19:49:28 BST: 1.1
   Minor cleanups.

2005-08-03 23:37:14 BST: 1.0
   Initial Release.

Stuart Brady