+.B load i2c [baudrate]
+This loads the i2c or drivers into the kernel and changes the permissions
+on the associated /dev/ entries so that the current user has access to
+them. Optionally it will set the I2C baudrate to that supplied in Kb/sec
+(or as close as the Pi can manage) The default speed is 100Kb/sec.
+
+Note: On recent kernels with the device tree enabled you should use the
+raspi-config program to load/unload the I2C device at boot time.
+(or disable the device tree to continue to use this method)
+
+.TP
+.B load spi
+This loads the spi drivers into the kernel and changes the permissions
+on the associated /dev/ entries so that the current user has access to
+them. It used to have the ability to change the buffer size from the
+default of 4096 bytes to an arbitrary value, however for some time the
+Pi Foundation have compiled the SPI device driver into the kernel and
+this has fixed the buffer size. The way to change it now is to edit
+the /boot/cmdline.txt file and add on spdev.bufsiz=8192 to set it to
+e.g. 8192 bytes then reboot.
+
+Note: On recent kernels with the device tree enabled you should use the
+raspi-config program to load/unload the SPI device at boot time.
+(or disable the device tree to continue to use this method)
+
+.TP
+.B gbr
+channel
+
+This reads the analog to digital converter on the Gertboard on the given
+channel. The board jumpers need to be in-place to do this operation.
+
+.TP
+.B gbw
+channel value
+
+This writes the supplied value to the output channel on the Gertboards
+SPI digital to analogue converter.
+The board jumpers need to be in-place to do this operation.
+
+
+.SH "WiringPi vs. BCM_GPIO Pin numbering vs. Physical pin numbering"
+
+.PP
+The quickest way to get a list of the pin differences is to run the command
+.TP
+gpio readall