TUNES random comments

Jecel Mattos de Assumpcao Jr.
Sat, 5 Nov 94 01:26:26 EDT

Just a few, quick ideas:

- Organization

  This is certainly the very first thing to do. After it is done,
however, I wonder if everyone will still receive every message
from all of the subgroups or if there will be sublists of some

- Survey

  Very important. Though this will start next week at the very
earliest, I can't resist pointing people who have been thinking
about objects, agents and security to Sun's SpringOS project.
You can get lots of papers about it at by
looking up research.

  For those of you who don't know about organizing object oriented
systems using reflection, I would recomend studying Sony's Apertos
OS ( or look in OOPSLA'92 ).

- Documentation

  I have used AmiPro, PageMaker, Interleaf Publisher and Latex so
far to document my project, but have recently converted to HTML.
This would be great even if the formatting is a little limited -
you can insert charts and other figures as GIF files. Even those
who don't have WWW access ( I normally don't ) could receive the
latest version of the docs in a ARJed or TAR-GZIPed file uuencoded
by mail and read them locally with Mosaic or Netscape.

I have found it easy to create drawings with any tool I want in
Linux and convert them to GIF via xv. I don't know if there is a
easy way in Windows, though I know how to convert PCX to GIF.

- Security

  Just a note to Francois-Rene and Chris who were wondering about
386 LDT segments: in the 286 OO OS I designed in 87 we used this
idea. Each task will need about two GDT entries ( one for its TSS
and another if it has a LDT ), so you are limited to about 2K tasks.
Each task can have its own LDT with up to 8K entries, so 500 tasks
with 3 objects each is a very tiny fraction of the 286's architectural
limits. But I would not use this feature today, as this would make
it impossible to port to other CPUs.

Jecel Assumpcao Jr
Merlin Computers
+Laboratorio de Sistemas Integraveis - University of Sao Paulo - Brazil
+Pontificia Universidade Catolica de Sao Paulo