AWCTTYPA@UIAMVS.BITNET ("David A. Lyons") (01/23/89)
>Date: Sun Jan 22 16:01:19 1989 >From: jason@lakesys.lakesys.com >Hi - I was just curious as to how you got Nifty List to read the data >file (NLIST.DATA? Whatever...). I did a dumpobj of its headers, and I >don't see an Init segment. Correct--there is no INIT segment there. Don't need one, although I tried that method at one point (never got it working quite right). CDAs have two entry points: one for when you choose it through the CDA menu, and a second one that is called by the Desk Manager whenever DeskStartup or DeskShutdown is called. The system calls DeskShutdown immediately after all the DAs are loaded, during boot, so all DAs get a chance to do whatever initialization they need. Screen dimmers and macro programs can install HeartBeat interrupt tasks, Nifty List reads NLIST.DATA, etc. The initialization routine will be called whenever you switch between ProDOS 8 and GS/OS (or ProDOS 16) and whenever an application that supports NDAs starts or quits. The DAs that only need one-time initialization, like Nifty List, just need to set a flag internally after init-ing once & not do anything further if the flag is already set. > jason@lakesys > (Not your average iconoclast) --David A. Lyons bitnet: awcttypa@uiamvs DAL Systems CompuServe: 72177,3233 P.O. Box 287 GEnie mail: D.LYONS2 North Liberty, IA 52317 AppleLinkPE: Dave Lyons