Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!usc!jarthur!elroy.jpl.nasa.gov!ucla-cs!tj
From: tj@oahu.cs.ucla.edu (Tom Johnson)
Newsgroups: comp.sys.mac.programmer
Subject: DRVRs and installing them
Message-ID: <32641@shemp.CS.UCLA.EDU>
Date: 7 Mar 90 18:20:16 GMT
Sender: news@CS.UCLA.EDU
Reply-To: tj@cs.ucla.edu (Tom Johnson)
Distribution: usa
Organization: UCLA Computer Science Department
Lines: 28

I am about to try writing a device driver for the first time.  I have
looked through all of my old MacTutors and Inside Mac and I must confess
I am a little intimidated. (a little?  Actually a lot) The only example
I could find was the IAC driver in the 10/88 issue.  Could someone please
point me to a simpler example of writing DRVRs in Pascal (preferably)
or C?

I am also going to have to install this thing in the system heap using
an INIT.  Does anybody have some sample code on how to find an empty
slot in the driver table?
Once I find the empty slot I guess I would just do the following:
   GetNamedResource
   GetResInfo
   SetResInfo	{change ID to the open slot in the table}
   OpenDeskAcc	{open the driver}
   DetachResource
   SetResInfo	{restore the original ID}

Is this basic outline correct?

Thanks,

Tom Johnson

       Tom Johnson      UCLA Computer Science Department 
			3413 Boelter Hall, Los Angeles CA 90024 (213)825-6952
			UUCP:      {uunet,rutgers,ucbvax}!cs.ucla.edu!tj
			Internet:  tj@cs.ucla.edu