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From: osborn@ux1.lbl.gov (James R Osborn)
Newsgroups: comp.sys.mac.programmer
Subject: SAMPLE cdev in C
Summary: How in the "C" do you do it?
Keywords: cdev, CDEV, LSC
Message-ID: <1845@helios.ee.lbl.gov>
Date: 5 Feb 89 22:44:29 GMT
Sender: usenet@helios.ee.lbl.gov
Reply-To: osborn@ux1.lbl.gov (James R Osborn)
Organization: Lawrence Berkeley Laboratory, Berkeley
Lines: 44



Greetings Wise Ones,

	I have been attempting to do the SAMPLE cdev given in IM-V p.323
using LSC 3.01p3.  I was simply trying to do a direct translation from the
example in Pascal to C.  When I try to run the damn thing (in the control
panel), the ICN# shows up properly and I can select it.  Sometime soon
after it has drawn in the gray background and the specified nrct, it crashes
(causing my MacsBug to take over) with an address error at 0x3.  The thing
crashes before the dialog items are drawn, but I don't know if the control
panel calls my cdev function first or not.  My resources appear to be in
ship shape.
	My first thought was that my function is not using the proper
calling conventions or something along these lines.  I can see no problems
however, and here is how I declared the function:


pascal long main (message, Item, numItems,
				CPanelID, theEvent, cdevValue, CPDialog)
int		message, Item, numItems, CPanelID;
EventRecord	*theEvent;
long		cdevValue;
DialogPtr	CPDialog;


	I don't know how to prod around with MacsBug very effectively, so
I don't really know where the thing is bombing.  Aside from any suggestions
on this problem, can anyone offer any tips on debugging code resources with
LSC?  I could not find any information about this in the manuals.  The only
thing I could think of (in this particular case) would be to write an 
application that would call this thing and mimic the control panel's inter-
action with it.

	BTW, if people who don't know how to write cdev's are interested in
this C example, I shall post it (when it works) in (I think):

				 comp.sys.mac.sources

THANKS in advance for any help,

				James R. Osborn
				osborn@ux1.lbl.gov
				Lawrence Berkeley Laboratory