Path: utzoo!utgpu!watmath!iuvax!purdue!bu-cs!polygen!jerry
From: jerry@polygen.uucp (Jerry Shekhel)
Newsgroups: comp.sys.atari.st
Subject: Re: Multitasking on the ST (Minix)
Message-ID: <527@polygen.UUCP>
Date: 14 Aug 89 15:10:30 GMT
References: <89081310545051@masnet.uucp> <1043@rex.cs.tulane.edu>
Reply-To: jerry@polygen.UUCP (Jerry Shekhel)
Organization: Polygen Corporation, Waltham, MA
Lines: 39

In article (Dzung Hoang) writes:
>In article (DAVID MEGGINSON) writes:
>>
>>From what I've heard, Minix is very restrictive with memory.  Each
>>program is allowed a maximum of 64k, and there is not VM paging.  A cute
>>toy, but useless for anything but learning.
>>
>    Minix for the IBM-PC's are restricted to 64K due to the PC's
>architecture.  The 68000 in the ST does not have any such restriction so it
>can run programs larger than 64K.  It is not "useless for anything but
>learning."  Post a message in comp.os.minix and you'll see what I mean.
>
>    I used to have an ST but now own an AT compatible.  I wish I still have
>the ST (and a big hard drive) to run minix.
>

I've also had both the ST and the PC versions of Minix.  The PC version's
limitation is not 64K.  A program may have 64K of code AND 64K of stack/data,
for a total program size of 128K.

This limitation is used for two reasons: it is reasonable for a teaching OS
and most Minix utilities (MOST -- no 16-bit compress!), and it makes forking
EXTREMELY fast and simple.

Sure, you can run monstrous GNU stuff on ST Minix -- that is its strength --
unlimited program size.  But try to run anything that forks a lot, like
extracting programs from a shell archive, and you'll see the ST slow down
to an unbelievable crawl, while my 8MHz AT zips along on the same job.
And worse, try to run a program which forks and does not immediately exec(),
and you'll be begging for an MMU!

But just like the above poster, I sure wish I had a big hard drive for my
ST Minix!
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+--------------------+-----------------------+-------------------------------+
|                    |  Polygen Corporation  |           UUCP:               |
|  Jerry J. Shekhel  |   Waltham, MA 02254   |  {princeton, mit-eddie,       |
|                    |    (617) 890-2888     |  buita, sunne}!polygen!jerry  |
+--------------------+-----------------------+-------------------------------+