Path: utzoo!attcan!uunet!sco!johnwe
From: johnwe (John Weber, Celtic sysmom)
Newsgroups: comp.arch
Subject: Re: Transputer based systems.
Summary: Transputer problems
Keywords: transputer, inmos, unix
Message-ID: <1133@scovert.sco.COM>
Date: 23 Sep 88 21:40:34 GMT
References: <253@uceng.UC.EDU>
Reply-To: johnwe (John Weber, Celtic sysmom)
Followup-To: comp.arch
Distribution: na
Organization: The Santa Cruz facility for the curably sane
Lines: 49

In comp.arch, rsexton@uceng.UC.EDU (robert sexton) discourses on Transputer based systems., thusly:
> being a fan of parallel system and their advantages, I was wondering why
> the transputer has not gotten off the ground as a viable system.  It seems
> pretty feasable, as well as very cost-effective.  I imagine a machine with
> several transputers, each running unix.

	The major problem with transputers in a multi user (UN*X ish OS)
	environment is the complete lack of memory management, or any 
	provision for external memory management.  While this is all well
	and good for a single user PC, where nobody really cares if one
	process stomps another process, it is not really the acceptable
	answer for a multiuser system or a system on a network.  If a process
	breaks in just the right way, it could take out the whole network.

	There is also the problem that a user can control task switching,
	and can effectively shut it off, with a little thought.  This is
	also a bad thing.  The processor also has a few design things which
	I personally feel a bit uncomfortable with, such as a lack of a
	barrel or funnel shifter combined with a bit of a problem in the
	microcode which causes the processor to hang for a LONG time
	if you try to left shift 7fffffffh, or distinctly too few registers.
	I also have a bit of a problem with the message security.

	On the other hand, they are wonderful chips for parallel processors,
	controllers, and PCs.  Massively fast, hardware multitasking,
	and other wonderful things.  Basically, in any aplication where 
	interprocess security is not needed they, are great.

> Thanks in advance for your input.
> 

	No prob...

> 
> Robert Sexton, University of Cincinnati
> rsexton@uceng.uc.edu tut.cis.ohio-state.edu!uccba!uceng!rsexton
> Box Full O' Transputers... The Breakfast with MIPS
> I do not speak for UC, They don't speak for me.


-- 

"In the fields of Hell,               John Weber, ...!uunet!sco!johnwe   
 where the grass grows high,              @ucscc.ucsc.EDU:johnwe@sco.COM 
 are the graves of dreams,                                               
 allowed to die."  -- Author unknown   Celtic sysmom  with an ATTITUDE!  

 Any opinions expressed are my own, and bear no relationship to those
 of my employers, to the best of my knowlege.