The Linux/IrDA project has undertaken some changes in the program code, which you should know to understand some possible confusions with older documentation, which you shouldn't use anyway.
Some caveats in the documentation have been caused by changes of the following concepts, device names and parameters. I hope I have got them alright now, they confused me sometimes, too. The new style stuff works from Kernel 2.2.15 / 2.4.0. Some important changes were made again in Kernel 2.6, not all of these are mentioned in this document yet, I will fix that hopefully soon. Anyway I recommend not to use any earlier kernel version than 2.6. This document will describe differences to the kernel 2.4 series in the appropriate places to provide documentation for situations where you must use kernel 2.4, which is hopefully rare. You should always use current Kernel, irda-utils and documentation.
For 2.0.x kernels Linux/IrDA support worked in a totally other way (only user-land programs) and is no longer supported by the Linux/IrDA project. Since 2.1.131 and 2.2.0 it is part of the kernel.
The major device number of the irda device changed from 61 to 161 (as far as I remember there was also a major number 60 around, too), also there have been different and now obsolete minor device numbers around, see the list of current device numbers below.
The irmanager is obsolete now, its tasks are now achieved by irattach.
The module name /dev/ircomm_tty changed to /dev/ircomm-tty , but there are other modules around which use either "-" or "_" in there names, this might be confusing.
The device names /dev/irnine and /dev/ircomm_new are obsolete.
IrLPT is handled by IrCOMM now. So all references to irlpt_server are obsolete.
From irda-utils 0.9.15 the behaviour of the -s option of irattach has changed. The option must not use the parameter 1 anymore.
The toshoboe driver for Toshiba laptops has been removed from 2.6 kernels.
Some important changes (e.g. for module names) were made in Kernel 2.6, these are not mentioned in this document yet, I will fix that hopefully soon.