Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!mcvax!botter!ark!Patrick From: Patrick@ark.cs.vu.nl (Patrick van Kleef) Newsgroups: comp.sys.atari.st Subject: Mac Emulator (idea!) Message-ID: <870@ark.cs.vu.nl> Date: Tue, 23-Dec-86 21:12:12 EST Article-I.D.: ark.870 Posted: Tue Dec 23 21:12:12 1986 Date-Received: Wed, 24-Dec-86 21:11:36 EST Organization: V.U. Informatica, Amsterdam, the Netherlands Lines: 27 Keywords: Preventing bus errors *** MUNCH MUNCH MUNCH *** Just an idea: The most frequent error that occurs using the Mac Emulator, is a bus error. This happens when programs start writing at locations they're not allowed to on the Atari ST. Usually it means the software wasn't 'perfect', not in accordance with the Apple Programming Guidelines. People tell me there is a way of preventing bus errors on the ST. This type of error is generated by one line of the Glue chip, the so called BERR line. Now what if we disconnected that line? In theory bus errors would be impossible. Would it affect 'normal programs'? Will more Macintosh programs run? Is there anyone who can figure this out? Dave Small writes, the most frequent error is the bus error that occurs when Mac programs write at location 0, Ram at the Mac, Rom at the ST. This action has -as far as I know- no effect on the working of a program on the Mac. But on the ST, a bus error occurs and the program fails to run. Would a switch, that disconnects the BERR line on the Glue have the same effect as on the Mac. Namely that programs run without further failure? I think it would increase the amount of good working Mac software a lot. As I'm too much of a kludge concerning hardware (and software too, for that matter), I'd like the opinion of some experts. Moshe, do you have any idea?