Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!rochester!ritcv!cci632!rb From: rb@cci632.UUCP (Rex Ballard) Newsgroups: net.micro.atari16 Subject: Re: Interrupt service routines Message-ID: <259@cci632.UUCP> Date: Fri, 25-Jul-86 13:06:42 EDT Article-I.D.: cci632.259 Posted: Fri Jul 25 13:06:42 1986 Date-Received: Fri, 25-Jul-86 21:37:31 EDT References: <389@atari.UUcp> Reply-To: rb@ccird1.UUCP (Rex Ballard) Organization: CCI, Rochester Development, Rochester, NY Lines: 32 Summary: Thanks, Question, Warning. In article <389@atari.UUcp> dyer@atari.UUcp (Landon Dyer) writes: >In article , SMB.MDC@OFFICE-1.ARPA writes: >> Is there a way to replace the MFP interrupt service routines with a user >> written version? I've been looking for a table which contains the address of >> the ISRs, but haven't been able to locate it. > >68901 interrupts are based at 0x100: > >> Is the BIOS in a different location in the 1040ST? I have the ST >> internals book and the BIOS listing doesn't seem to be correct for my >> computer. > >The ROMs for the 520ST and the 1040ST are identical. The BIOS listing >you have is from the first RAM-loaded release of the system, not from >the later ROMs. The listing is useful in that it gives examples (e.g. >how to twiddle the ST's hardware), but DON'T expect the addresses or >code in the ROM to match your listing. >-Landon Dyer, Atari Corp. {lll-lcc,lll-crg!vecpyr}!atari!dyer Thank you for giving the information. Just out of curiousity, did you fix the perverse usage of the high address bits so that a 68010 or 68020 could be used in place of the 68000? You forgot to caution against jumping into the ROM for any reason. This shouldn't be necessary for the ST since almost all of the "useful routines" are available as "system calls" or exceptions. Let's hope we can avoid the "hacker tactics" used on the Atari 800, Apple II, and IBM-PC. Otherwise Atari can't come up with better versions and bug fixes. Landon, maybe you could give some "ground rules" about "hostile applications" that "take over" vectors for private use. Definately not reccomended if Atari plans to go to multi-tasking in a future ROM release.