Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!tut.cis.ohio-state.edu!ucbvax!hoptoad!tim
From: tim@hoptoad.uucp (Tim Maroney)
Newsgroups: comp.sys.mac.programmer
Subject: Re: The 80486 is braindead (was Re: Xerox sues Apple!!!)
Message-ID: <9432@hoptoad.uucp>
Date: 29 Dec 89 23:39:45 GMT
References: <14960@boulder.Colorado.EDU> <213@amix.commodore.com> <25347@ubvax.UB.Com> <9378@hoptoad.uucp> <25470@cup.portal.com>
Reply-To: tim@hoptoad.UUCP (Tim Maroney)
Organization: Eclectic Software, San Francisco
Lines: 17

In article <25470@cup.portal.com> ts@cup.portal.com (Tim W Smith) writes:
>What I don't understand is why you need to use a TAS instruction on
>a Mac.  Do you have another bus master on your motherboard?

It's a convenient way to synchronize between interrupt levels without
disabling interrupts, even if it is a bit of overkill for the job.  I
suppose that BCLR could do much the same thing, but I didn't know about
that instruction when I was writing the code in question.  Still, so
far as I know, it's been tested on all Mac models and there has not
been a problem with TAS.

From what you say, if there is a problem the system should hang the
first time TAS is invoked, and this certainly has not happened.
-- 
Tim Maroney, Mac Software Consultant, sun!hoptoad!tim, tim@toad.com

Never ascribe to stupidity what can adequately be explained by malice.