Getting SIGIO to work with a homemade driver on a Sun

[Roderic Taylor]

   SunOS 4.0.3, Sun 3/160

   I am writing a simple driver to read data from an external
device.  I want SIGIO to work with this driver, so I can get
an interrupt when more data is ready to be read from the device.
How do I get that to work?  If the device generates an interrupt
which is caught by the kernel interrupt routine for the driver,
will that generate a SIGIO interrupt automatically, or do I have
to do something special in the interrupt routine myself?

                                          --Roderic T