Path: utzoo!attcan!uunet!hodge!pnet06!thecloud
From: thecloud@pnet06.cts.com (Ken Mcleod)
Newsgroups: comp.sys.mac.programmer
Subject: System 6.0 breaks my cdevs! revisited
Message-ID: <227@hodge.UUCP>
Date: 14 Jun 88 11:17:17 GMT
Sender: rusty@hodge.UUCP
Organization: People-Net [pnet06], Orange, CA
Lines: 21


 Well, after looking more closely, I discovered the reason why various
cdev's were breaking under System 6.0: they check for the presence of
certain packages in the System file (usually PACK 7 or PACK 4) that
no longer exist! (except in the ROM). Even Apple's Sample cdev in IM V
does this (although there's a brief disclaimer that you "really should"
check for the packages in ROM). Ouch.
 
 Then there's the MultiFinder test. Most sample source code I've seen
(actually, ALL) checks for MultiFinder's presence by testing to see
whether the WaitNextEvent trap is implemented. Now, in System 6.0,
it's implemented ALL THE TIME, whether you're in MF or not. So if
application X assumes it's running under MultiFinder when it isn't,
well, look out.

 Question: how do you detect MultiFinder's presence or absence under 6.0?

Ken McLeod =========================     .......     ======================
UUCP: {crash uunet}!pnet06!thecloud     :.     .:    Chief Weapons of UNIX:
ARPA: crash!pnet06!thecloud@nosc.mil   :::.. ..:::   "Fear, surprise, and
INET: thecloud@pnet06.cts.com             ////        ruthless efficiency."