A.P. Lawrence

Writing Unix Device Drivers

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This is five years old now, but it's hard to find good books on this subject, and particularly hard to find references to SCO.

This book does reference SCO (though 3.2v4.2), and has enough examples to get you started.

Why would you want to do this? Most of us have no pressing need to write driver code. But understanding how such code actually is written can teach you quite a bit, and make otherwise incomprehensible problems in someone else's driver easier to identify, at least.

Sometimes the exercise can even be useful. I once had a combination of a particular computer and printer that just did not work well, for no apparent reason. Both my budget and my general stubbornness rebelled against just accepting that and buying something else, so I set out to write a printer driver that would help me find the problem.

That driver is discussed here in my Device Drivers article, but the really interesting thing was that I never got to use the debugging features because for reasons I still don't understand, the printer immediately began working perfectly with the new driver!