[fa.info-mac] Creating Desk Accessories

info-mac@uw-beaver (info-mac) (08/18/84)

From: cohn%UCBONYX@Berkeley
	Good news. I got the desk accessory to work. I found that the
Linker prefixes a code segment with four bytes which (I believe) specify
the segment number of the code (what a coincidence).  The MakeDRVR 
program which I had to write to convert CODE types into DRVR types was
changed so that it not only detaches the resource from the application
but purges those nasty four bytes at the beginning. My desk accessory was
born. For anyone interested, my first desk accessory inverted a window
with the word "Fleetwood Mac" as often as possible (nothing very useful,
unfortunately).

	I added several copies of the same accessory to my system file
and opened all of them from the apple menu and found that more than four
accessories which need time really begin to slow down the Mac.

	If you're interested in creating a desk accessory the way I
did and were confused when reading my last message, below is a procesure list:

	1)	write your desk accessory in the assembler.
		Make sure that you supply all of the pertinent
		data before your code as specified in the 
		Device Manager or Desk Manager documentation.

	2)	You need Open, Close and Run routines.

	3)	Copy your CODE type with ID = 1 to a DRVR type
		with a destination ID between 0 and 31.

	4)	Use the Resource Mover to copy the DRVR type
		from your destination file you created above
		and paste it into the system resource file.

	5)	Quit Resource Mover and enjoy your new Desk Toy.

					Ted Cohn
					cohn@ucbonyx  (via ucbvax)

P.S	I'll try to supply the machine language program to convert
	CODE to DRVR next time if your not sure how to do it. Bye.