Path: utzoo!utgpu!attcan!uunet!seismo!sundc!pitstop!sun!amdcad!ames!pasteur!agate!ucbvax!STONY-BROOK.SCRC.SYMBOLICS.COM!jrd From: jrd@STONY-BROOK.SCRC.SYMBOLICS.COM (John R. Dunning) Newsgroups: comp.sys.atari.st Subject: Register saving for BIOS traps? Message-ID: <19880922163903.5.JRD@MOA.SCRC.Symbolics.COM> Date: 22 Sep 88 16:39:00 GMT Sender: daemon@ucbvax.BERKELEY.EDU Organization: The Internet Lines: 11 I think I remember a discussion about this a while ago, but don't remember the outcome. I believe it's necessary to save (some) registers around BIOS and XBIOS traps. The question for today is: which ones? Is there any rhyme or reason to which registers get trashed inside the trap? A related question; am I correct in assuming that GEMDOS traps don't require register saving? Thanks in advance for any info.