Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site psivax.UUCP Path: utzoo!linus!decvax!ittatc!dcdwest!sdcsvax!sdcrdcf!psivax!tommie From: tommie@psivax.UUCP (Tom Levin) Newsgroups: net.micro.apple Subject: Re: Interupts on a apple ][+ Message-ID: <829@psivax.UUCP> Date: Fri, 1-Nov-85 15:41:24 EST Article-I.D.: psivax.829 Posted: Fri Nov 1 15:41:24 1985 Date-Received: Tue, 5-Nov-85 05:41:40 EST References: <76@noscvax.UUCP> Reply-To: tommie@psivax.UUCP (Tom Levin) Organization: Pacesetter Systems Inc., Sylmar, CA Lines: 26 Keywords: Apple II interrupts In article <76@noscvax.UUCP> medin@nosc (Ted Medin) writes: >card and have come to the conclusion that the areg is not preserved >for the interupt code. Specifically when I get an interupt the areg is >always an 8 or 18 hex. This makes it very difficult to return to the >interupted code with the regs restored. > Can someone out there confirm this architecture failure on the ][+ ?????? First off, the word interrupt has 2 r's. Now then, although I don't exactly understand your problem as stated, I will give you my knowledge on 6502 interrupts. NO REGISTERS ARE SAVED FOR YOU!!! Yes, you must save all of the registers yourself and restore them after the "rti" (return from interrupt) command. I don't consider this an architecture failure. later... -- __________________________________________________________________________ Tom Levin {ttidca|sdcrdcf|logico|scgvaxd|bellcore}!psivax!tommie You've seen those car stickers that say "Baby on Board"??? _________ I want one that says: / \ / Psychotic \ / On \ \ Board / \___________/