Linux Control and Measurement Device Interface (comedi)

		David Schleef
		<ds@stm.lbl.gov>


A new minor version of comedi, 0.6.0, is now available at
<ftp://stm.lbl.gov/pub/comedi/>.  The change in minor version
level to 6 represents a complete redesign and rewrite of
the kernel interface.  Because of this, 0.6.0 is almost
completely incompatible with previous versions.

This redesign was necessary for current and future growth
of comedi.  The current needs that have been addressed are
SMP and RT compatibility, the need to be more friendly to
high-level programming, and an overall simplification of
the interface.  Using the 0.6 series should eventually be
easier and more understandable.

The major changes from the 0.5 series are:

	- Comedi devices are now divided into "subdevices",
	  such as a A/D subsystem or D/A subsystem, instead
	  of channels.  This eliminates much of the redundant
	  information and coding that was present in the 0.5
	  series, and also allows proper locking of devices
	  necessary for proper SMP and RT performance.
	
	- The 0.6 series will allow multiple methods for
	  data transfer from hardware to your user-level
	  process, including read()/write(), ioctl(), and
	  mmap(), giving users needed flexibility.
	
	- Hardware drivers that are real-time compatibile will
	  now be able to perform RTLinux tasks timed by device
	  interrupts.

Upgrading to 0.6 should not be too difficult, although it
will require editing and recompiling all programs that use
comedi, since the interface has changed.

Comedi includes hardware drivers for many boards.  See ./drivers
for details.

If you want to add support for another hardware device, you
will want to look at the comedi hardware driver writing HOWTO
in the doc directory.  It is fairly simple to write a new hardware
driver for comedi, but I am always willing to answer any questions
you might have.

Comedi may be freely distibuted and modified in accordance with the
GNU General Public License.