[PYTHONMAC-SIG] CFM68K considered harmful

[Jack Jansen]

Folks,
apparently Apple has sent out a warning that CFM68K in its current
form is not stable. I've appended the note as I saw it, from TidBits
<http://www.tidbits.com/tb-issues/TidBITS-356.html>.

It turns out that if an interrupt routine is called for a CFM68K
application this may mess up A5. The CFM68K application isn't bothered
by this, but if the interrupt happened while a Classic application was
running this application will loose A5 and probably proceed to crash
in a glorious way.

Since Python uses GUSI which uses I/O completion routines this means
that the CFM68K version of python is potentially dangerous too. 68K
Python users should decide for themselves whether they want to switch
back to the Classic 68K Python version or continue to live dangerously.

Here is the TidBITS article:

**Disable the CFM-68K Runtime Enabler** -- If you use a Macintosh
  with a 68K processor, Apple is recommending that you disable the
  CFM-68K Runtime Enabler either by using an extensions manager or
  by removing it from your System Folder. Some applications that use
  the CFM-68K Runtime Enabler can crash your Macintosh, possibly
  causing data loss and other problems. This problem does _not_
  affect Power Macs.

<http://www.macos.apple.com/macos/cfm-68k.html>

  The Code Fragment Manager (CFM) was originally developed for Power
  Macs and lets Power Mac applications use shared code libraries
  (trust me, they're neat). Later, Apple ported the CFM backwards to
  68K machines to make it easier for developers build 68K versions
  of Power Mac applications. Those 68K applications are just now
  starting to appear, although plenty more are in development.

  However, Apple now admits to a problem with the 68K version of
  CFM, and it can't be used reliably in all cases. Though this bug
  doesn't impact every program that uses CFM-68K, there's no simple
  way to know which applications are affected. Programs using CFM-
  68K include OpenDoc, Cyberdog, Apple Media Tool, LaserWriter 8.4
  and 8.4.1, Microsoft Internet Explorer 3.0b1, and the preview of
  AOL 3.0. If you use any of these programs, Apple recommends you
  revert to earlier versions or stop using them. If you disable the
  CFM-68K enabler and try to use one of these applications, you'll
  see an error, but no damage will be done. Apple is working on a
  fix, but there's no public timetable for when a solution might be
  available. [GD]

--
Jack Jansen             | ++++ stop the execution of Mumia Abu-Jamal ++++
Jack.Jansen@cwi.nl      | ++++ if you agree copy these lines to your sig ++++
http://www.cwi.nl/~jack | see http://www.xs4all.nl/~tank/spg-l/sigaction.htm 

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