Rekursiv chip (pretty long)
J Lothian
|>
|> Does anyone know what happened to the Rekursiv chip, which was
|> a microprocessor built in the UK? I think there was a write-up
|> on it in "Byte" a couple years ago.
[I'm crossposting this to comp.arch, since it seems relevant.]
Welll... It's an interesting and somewhat long story. The upshot
of it is that (a) the company building the machine failed to get a
patent on it in Japan, (b) by the time the machine had gone from
lab prototype to marketable board, the 486, Sparc &c had come along
and the rekursiv was more or less obsolete as a consequence, (c) Linn
(the company building it, who normally make expensive hi-fi) were in
financial difficulties, and couldn't really afford the project, (d)
nobody at Linn understood the machine, or had the foggiest idea how
to market it, or who to market it to, (e) the Linn van driver drove
the Linn van into the side of David Harland's (principal Rekursiv
architect) Porsche and Linn wouldn't pay for the repairs, which was
the last straw as far as David was concerned, and he stopped coming
in to work, and (f) Linn then shut the project down.
They said at the time that they were putting it into a state
of 'hibernation', but I think that it's a fair bet you won't see
it again. The name of one of the Rekursiv chips was subsequently
re-cycled by Linn as the name of the decoder for their new CD
player ('Numerik' was originally the Rekursiv's ALU chip).
The full chipset was Numerik (ALU), Logik (sequencer), Objekt (object-
oriented MMU) and Klock (various timers &c).
It's a great shame. In retrospect, though, it's easy to see that
the project was seriously out of touch with reality: the Rekursiv
was designed in the days when Vaxes ruled the roost; by the time
the design had been condensed down to the 4 monster gate-arrays, hefty
PCs and Sparcstations &c had started to appear, and the machine just
couldn't hold its own. It could only really have succeeded if it had
been backed by one of the really big computer manufacturers, who
could have made the investment required to keep it ahead of the
competition.
It was a really interesting and unusual design: the main memory was
in effect a persistent object store, with every object having its type,
size and position in memory known in hardware, so that (for example) the
hardware could prevent you from 'running off' the end of an array and
corrupting surrounding memory. Paging of objects into and out of main
memory was handled by the host machine (generally a Sun 3), and was
completely transparent, even at the microcode level. This meant that
you could write arbitrarily complex algorithms in microcode, even
recursive ones, hence the machine's name. Every object had a unique
identifier (a 40-bit number), and the MMU chip would translate that
into the object's store address (if it was in main memory). Since only
the MMU knew the object's address, an object could be moved around
in memory without having to update references to it (since they were
in terms of its object number); this made garbage-collection particularly
straightforward.
The support software (microsimulator and so forth) was
written to run under X10, and wasn't well enough behaved to run with
the X10/X11 protocol converter that went the rounds for a while, so
they were well and truly stuffed when X11 started to gain serious
acceptance (particularly given that the X10 that we had wouldn't run
under sunos 4.*).
I'm not sure what happened to the people on the project after it was
shut down. One of them (Brian Drummond) stayed on at Linn to provide a
certain amount of support for Rekursiv users (about 30 machines were
sold) and to try his hand at loudspeaker design. Ian Ellsley was last
heard of in China, swearing he'd never touch another Sun again. Bruno Beloff
worked for Oracle in Chertsey for about 2 weeks, before deciding that
Surrey didn't suit him and going to South Africa to take photographs of riots.
Duncan McIntyre was apparently heading for France. David Harland is rumoured
to be alive and well, but working on something much more ambitious :-).
I spent two and a half truly ghastly years cooped up in a poky little
office* in Edinburgh University's amazingly unfriendly Computer Science
department, microcoding a Prolog instruction set for the Rekursiv, being
yelled at for no apparent reason by other members of staff, and generally
having a thoroughly miserable time, which makes it all the more
bizarre that I look back on the project with a certain amount of
affection even now. I still have a T-shirt (daft promotional effort)
with 'Rekursiv' written across the front in large colourful letters.
I think they only made about 20 or something; maybe it'll be valuable
some day. More to the point, I also have a full set of chip databooks
& software manuals &c. I have a QIC tape somewhere that may or may not
have a Rekursiv software release on it. There is apparently a PC version
of Lingo (the Rekursiv's principal language, very like Smalltalk), but
you'd have to ask Linn about that.
James
(rekursiv project survivor)
--
*actually, several offices: from time to time, someone would come
to my office and say 'Right, you're moving offices. Now.' and I would
just have to drop whatever I was doing and go. They never gave you any
notice, or for that matter any reason. I got the impression that they
did this just to foster a degree of paranoia among the staff.
Definitely a place to avoid.
-------------------------------------------------------
James Lothian | "It's life, Jim,
ja...@uk.ac.ed.caad | but not as we know it"
Derek Pappas
|> In article <57...@blue.cis.pitt.edu>, wbd...@pitt.edu (William B Dwinnell) writes:
|> |>
|> |> Does anyone know what happened to the Rekursiv chip, which was
|> |> a microprocessor built in the UK? I think there was a write-up
|> |> on it in "Byte" a couple years ago.
|>
|> in effect a persistent object store, with every object having its type,
|> size and position in memory known in hardware, so that (for example) the
|> hardware could prevent you from 'running off' the end of an array and
|> corrupting surrounding memory. Paging of objects into and out of main
|> memory was handled by the host machine (generally a Sun 3), and was
|> completely transparent, even at the microcode level. This meant that
|> you could write arbitrarily complex algorithms in microcode, even
|> recursive ones, hence the machine's name. Every object had a unique
So how did the recursive microcode work?
Was it written up in Byte?
--Derek
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ Derek Pappas +
+ wk tel: 503-696-4546 +
+ wk fax: 503-640-0960 +
+ email: dpa...@ichips.intel.com +
+ INTEL m/s: JF1-19 +
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Andrew Thomas
[Stuff about Rekursiv deleted]
>So how did the recursive microcode work?
Get hold of a copy of:
"REKURSIV: Object-oriented Computer Architecture"
David M. Harland
Published by Ellis Horwood Ltd
ISBN 0-7458-0396-2
Cost about (pounds) 30 - your milage may vary.
This contains most of the publicly available data. There
were some data books - but these are no longer available
as Linn Smart Computing folded 3 years ago.
>Was it written up in Byte?
Yes. I don't have the reference handy - there were some nice
photo's of the card and the reviewer made a reasonable job
of describing how it worked.
The book has some omissions but is probably as close to definitive
as you will get - the garbage collection code is wrong for instance.
If you have any specific questions I might be able to post answers - I
wrote a fair bit of microcode for the machine before I joined Linn,
and I also wrote the 68K/SPARC version of Lingo (the language for
which the REKURSIV was designed - yes you did read that correctly
:-)).
Andrew
Email = Andrew...@ncl.ac.uk
Phone = +44 91 222 8546 FAX = +44 91 222 8232
Mail = Department of Computing Science, The University,
Newcastle upon Tyne, NE1 7RU, Great Britain.
David Morning
>In article <33...@castle.ed.ac.uk>, jlot...@castle.ed.ac.uk (J Lothian) writes:
>|> In article <57...@blue.cis.pitt.edu>, wbd...@pitt.edu (William B Dwinnell) writes:
>|> |>
>|> |> Does anyone know what happened to the Rekursiv chip, which was
>|> |> a microprocessor built in the UK? I think there was a write-up
>|> |> on it in "Byte" a couple years ago.
>|>
>|> It was a really interesting and unusual design: the main memory was
>|> in effect a persistent object store, with every object having its type,
>|> size and position in memory known in hardware, so that (for example) the
>|> hardware could prevent you from 'running off' the end of an array and
>|> corrupting surrounding memory. Paging of objects into and out of main
>|> memory was handled by the host machine (generally a Sun 3), and was
>|> completely transparent, even at the microcode level. This meant that
>|> you could write arbitrarily complex algorithms in microcode, even
>|> recursive ones, hence the machine's name. Every object had a unique
It was designed by Linn Products in Eaglesham, Scotland. Linn are better known
for there mega expensive Sondek record turntables. All 'c's were replaced with
'k's for some bizarre reason so 'object' became 'objekt' etc etc...
Haven't heard anything of it since the initial announcement a few years back.
I suspect Linn have dropped the projec(k)t and gone back to what they know best,
making hi-fi gear.
>Was it written up in Byte?
I believe it was, some years ago - maybe 4?
Dave
--
J Lothian
|> Was it written up in Byte?
The Byte write-up was in the November 1988 edition, and was by Dick
Pountain. The last words of the article are
'I expect it to do well'. Hey ho.
Obligatory totally irrelevant piece of Rekursiv project folklore:
the name of the Rekursiv's ALU chip ('Numerik') was subsequently
re-cycled by Linn as the name of the signal-processing box on their
first CD player, which is probably as good a sign of the Rekursiv's
permanent demise as any.
|>
|> --Derek
|>
|> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
|> + Derek Pappas +
|> + wk tel: 503-696-4546 +
|> + wk fax: 503-640-0960 +
|> + email: dpa...@ichips.intel.com +
|> + INTEL m/s: JF1-19 +
|> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
James
--
Steven D. Majewski
There is also a chapter on the Rekursiv in a book a read last year,
and I *THINK* the book was:
AUTHOR Blair, Gordon.
TITLE Object-oriented languages, systems, and applications / edited
by Gordon Blair ... [et al.].
PUBLISHER New York : Halsted Press, c1991.
DESCRIPTION 378 p. : ill. ; 24 cm.
Includes bibliographical references and index.
SUBJECT TERMS Object-oriented programming (Computer science)
ISBN 0470217227
-Steve Majewski (804-982-0831) <sd...@Virginia.EDU>
-Univ. of Virginia Department of Molecular Physiology and Biological Physics