Xref: utzoo comp.arch:18402 alt.folklore.computers:5745
Path: utzoo!attcan!uunet!mcsun!hp4nl!charon!dik
From: dik@cwi.nl (Dik T. Winter)
Newsgroups: comp.arch,alt.folklore.computers
Subject: Re: Looking for a really odd computer
Message-ID: <2280@charon.cwi.nl>
Date: 4 Oct 90 00:44:17 GMT
References: <2721@crdos1.crd.ge.COM> <12857@encore.Encore.COM>
Sender: news@cwi.nl
Followup-To: alt.folklore.computers
Organization: CWI, Amsterdam
Lines: 41

(Cross-posted to alt.folklore.computers; followups go overthere.)
In article <12857@encore.Encore.COM> jkenton@pinocchio.encore.com (Jeff Kenton) writes:
 > From article <2721@crdos1.crd.ge.COM>, by davidsen@crdos1.crd.ge.COM (Wm E Davidsen Jr):
 > > The question is, has anyone ever made a general purpose computer with and
 > > odd word size? No one doesn't count, thank you bit slicers.
 > All in all, the answer to your question is probably "no".
 > 
The answer is most certainly 'yes'.  When I learned programming back in the
sixties we had an Electrologica X8 (originally designed by the Mathematisch
Centrum, now called Centrum voor Wiskunde en Informatica (CWI), later taken
over by Philips).  Word size was 27 bits (can you get odder).  I still can
quote from memory 67108864 (MAXINT+1).  It was the successor of the X1, also
with 27 bit words.  There were quite a few X1's and X8's installed; not only
in the Netherlands, but also in Germany for instance (Karlsruhe University if
I remember right).  The machine was ones complement.  Floating point used two
words.  I still have the programmer's manual next to me here at home.  And it
was certainly general purpose.  The machine we had was decommisioned in about
1976.

The machine had very interesting features.  I believe it was the first machine
that had a separate I/O processor.  And it was this machine and its
precursor that got Dijkstra to his semaphore stuff.

Further characteristics:  64 Kwords of memory of which 32 K directly
addressable (when I started only 32 K was enabled).  OS was simple: a
job consisted of an Algol 60 program, possibly followed by its data.
The system would fire up the compiler wich would compile the program
and initiate execution.  When done the next program was started.  Later
multi-tasking was implemented with four batch streams, each with its own
characteristics.  And again later a system was created that allowed
interactive operations, although that was for special occasions only.
There was another OS that would do Fortran programs but that was nearly
never used at our institute.  And initially job input was on 7-level
papertape (a special coding derived from IBM 7-level).  Later versions
allowed also 5-level (Baudot/ALCOR) coding, 8-level (ASCII) coding and
punched cards (IBM-029 modified).

Mmm, that is some time ago.
--
dik t. winter, cwi, amsterdam, nederland
dik@cwi.nl