NetNews Usenet Archive 1992 #27/NN_1992_27.iso/spool/comp/arch/10984

Text File | 1992-11-20 | 2.7 KB | 61 lines

Newsgroups: comp.arch
Path: sparky!uunet!zaphod.mps.ohio-state.edu!cs.utexas.edu!sun-barr!sh.wide!wnoc-tyo-news!lkbreth!trebor
From: [e-mail] (Robert J Woodhead)
Subject: Re: What happened to the UCSD p-System?
Message-ID: <[e-mail]>
Organization: Foretune Co., Ltd.
References: <[e-mail]>
Date: Sat, 21 Nov 1992 05:51:39 GMT
Lines: 50

[e-mail] (Lou Glassy) writes:
>Is any work going on in this area?  Or does performance pay
>more than portability?

The UCSD p-System had many advantages for its time.  Recall, back in
those dark ages, machines were slow, memory was tight (64k was huge)
and hard discs were non-existant.  Even floppies rarely had more than
150k on them.

So packing a decent OS that could run reasonable programs into such
environments was tough.  The p-System attacked this problem in several
ways:

1) p-Code instructions were highly optimized both for space and ease
of interpretation, which meant that the interpreters were small, and
the p-Code programs themselves were smaller than equivalent machine
code programs; so much so that usually OS+Interpreter+p-Code program
was smaller than the native machine code program alone!

2) That smaller size really helped when you consider the size and
speed of the storage devices.

3) p-Code was easy to compile for, which meant that the Pascal compiler
was small (ie: it could actually run on a 64k machine!)

4) It was portable, which meant that it was easy to support all the
gazillion different machines out there.

For it's time, the UCSD p-System was a great achievement, but like
all things, its time has passed.  I myself used the Apple Pascal
version to write Wizardry (14,000+ lines, originally done on a
64k, 2-floppy machine; full compiles took an hour!).

Wierd side story: When Wizardry was translated into Japanese, the
Japanese company that did the work (and from whose premises I am
writing this note) simply wrote p-System interpreters for all the
target machines, and we made minor modifications to the Wizardry
program to handle Japanese characters and syntax (the final version
let you choose at boot time if you wanted to play in English, Kana
or Kanji).  After we were done, we back-converted their interpreter
to run either standalone or under MS-DOS; I wrote Wizardry IV on a
NEC9801 MS-DOS machine that, after a suitable command line incantation,
promptly said "Welcome to Apple Pascal!"

(And yeah, I bought an extra copy of Apple Pascal for the NEC, too!)

--
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| Robert J. Woodhead, Biar Games / AnimEigo, Incs.    [e-mail] |
| AnimEigo US Office Email (for general questions): [e-mail] |