Re: Smallest system you've ever worked on?

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I think the PDP11-on-a-chip was post 11/23 (late '70s or early '80s) and was
called the T11 or Falcon. With my mind's eye, I can see the blue A4 manual
(I may even have a copy somewhere!)
I think it took a leaf from the 68000/68008 in that it could drive an 16/8
bit bus.
Now if this had been done a lot earlier, and RT11 was offered at a cheap
price on it,
how much of the market would  CPM86 and MSDOS have  had?

Regards, Graham Reid

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Re: Smallest system you've ever worked on?
On Fri, 30 Apr 2004 21:12:47 +0100, "Graham Reid"

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This was one of DEC's greatest lost opportunities. RT-11 was simple,
fast and a joy to program under, like CPM and MS-DOS wanted to be, but
never quite got to.
By choosing a crippled version of RSX, then requiring you to use a DEC
mini to write software, DEC managed exclude most of the young
developers who were driving the PC revolution. I was at DEC then, and
I think a lot of their bad decisions resulted from internal politics.


--
Jim McGinnis

Re: Smallest system you've ever worked on?
On Fri, 30 Apr 2004 16:50:32 -0400, in article

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Not really sure which was first there, but there were some similarities
between the devices.

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At that time 32 bit and VAX was were everybody was supposed to be going to
and dropping PDP-11's as quickly as possible.

Then again Ken Olson had at least a PDP-11/03 at home and still said
"No one needs a home computer".

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Ditto..


Like a lot of companies at the time inward not outward looking.
I left DEC in '83 and went onto other things.

--
Paul Carpenter        | snipped-for-privacy@pcserv.demon.co.uk
<http://www.pcserv.demon.co.uk/ Main Site
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Re: Smallest system you've ever worked on?
paul$@pcserv.demon.co.uk (Paul Carpenter) writes:

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Ken also famously called UNIX "snake oil".  I would think at least
half of the DEC machines at the time he said it were running UNIX.
DEC seemed to be about half a decade behind when it came to software.

--
Darin Johnson
    "You used to be big."
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Re: Smallest system you've ever worked on?
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Digital PDP-11 was first. The resemblance of Motorola microprocessors
and Digital minis is no accident: the original 6800 was as much of
PDP-11 as the Motorola engineers could squeeze on silicon of that time.

Motorola was an active OEM user of Digital minis before they started
their own microprocessor line.

The 68000 was a growth path from the 6800 root without looking at
the common ancestor (PDP-11) or the cousin (VAXen).

Some of the more distant cousins include the Data General Nova /
Eclipse line: it was created by some ex-Digital designers after
their idea of PDP-11 was put on hold.

Having programmer/user experience of them all.

Tauno Voipio
tauno voipio @ iki fi


Re: Smallest system you've ever worked on?
On Sun, 02 May 2004 13:43:02 GMT, Tauno Voipio


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Even trying to stretch my imagination to the limit, I can not see any
resemblance between 6800 and PDP-11. The 6800 with two accumulators
and one index register would be similar to Nova or (Honeywell
DDP-316/516). Perhaps some DEC 18 bit machines (such as PDP-15) might
have had a similar architecture, but I have not used these 18 bit
processors.
 
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The 68000 is somewhere between PDP-11 and VAX, but the similarities
between 6800 and 68000 are surprisingly few.

Paul


Re: Smallest system you've ever worked on?

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I'd have to agree. I've studied the instruction set and written
assembly language for both, and I see almost no resmblance in
philosophy, the general architecture or the layout of the
instruction set.

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The 68000 was more similar to the PDP-11 than the 6800 was, but
the 68000 still differed in basic philosphy from the PDP-11.

The most obvious difference was the dedicated address/data
registers in the 68K (which was more of an extension of the
accumulator/index-register design in the 6800) verses the
beautiful, orthogonal design of the PDP-11 where any register
could be used for anything.

--
Grant Edwards                   grante             Yow!  Of course, you
                                  at               UNDERSTAND about the PLAIDS
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Re: Smallest system you've ever worked on?
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Wasn't it one of those that was the subject of "The Soul of a New Machine",
the primal Silicon-Valley-burnout book?

Steve
http://www.sfdesign.co.uk
http://www.fivetrees.com



Re: Smallest system you've ever worked on?

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TSoaNM was about the development of the Eclipse (a 32-bit
virtual memory machine to compete with DEC's VAX line).

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Silicon Valley?!?!?  That's a bit insulting. Both DEC and DG
were in Massachusetts.  Ya know, those of us east of California
have indoor plumbing and electricty and phones and TV and the
internet and everything....

--
Grant Edwards                   grante             Yow!  These PRESERVES
                                  at               should be FORCE-FED to
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Re: Smallest system you've ever worked on?
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Ah, ok. Knew it was DG though ;).

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Oops. I'm in the UK. You all look the same from here ;).

Steve
http://www.sfdesign.co.uk
http://www.fivetrees.com



Re: Smallest system you've ever worked on?

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Machine",
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Not quite - there were the 16 bit Novas and Eclipses before
the 32-bit virtual memory Eclipse the book tells about.

There are still on my bookshelf the manuals for the AOS/VS,
the operating system for the 32-bit Eclipses.

Tauno Voipio
tauno voipio @ iki fi



Re: Smallest system you've ever worked on?
The nova was a 16 bit cousin of the pdp8.  I once had a room full of PDP-8's
and a single lonely Nova (4k). I simulated a full 4K pdp 8 on the 4K nova by
writing the PDP emulator in less than the bit difference between the two
processors. This worked quite well.

For months the core based NOVA had the PDP8 assembler permanately loaded,
putting new meaning into cross assembler's

Walter..

Steve at fivetrees wrote:

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Re: Smallest system you've ever worked on?
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Actually, it was their idea of a 16-bit computer that they literally
stole from DIGITAL. The PDP-11 was conceived AFTER they departed. - RM


Re: Smallest system you've ever worked on?

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Right. The Nova was what was about to be the PDP-11, but it was
held, as PDP-8's were still selling well, and that was not to be
disturbed. The designers got frustrated, moved to neighboring
town and started Data General.

Tauno Voipio
tauno voipio @ iki fi



Re: Smallest system you've ever worked on?

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A valid criticism.  I've only gotten my mine to live for a few minutes.

--
Darin Johnson
    "Floyd here now!"

Re: Smallest system you've ever worked on?

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Made one in the 70s using only sn7489's











Remove "HeadFromButt", before replying by email.

Re: Smallest system you've ever worked on?

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I was wondering just how much processing power would be needed to have a
model mimic ALL the activities of a cockroach - including hard realtime
requirement to avoid the rolled-up newspaper when the roach feels a breeze
from its rapid descent. Oh, and wheels would be cheating - has to be able
to run up walls and hang underneath decking ;)

What do you think? State machine and neural net in fpga? Or 3GHz processor?
We can achieve a lot with tiny amounts of processing power in embedded
systems, but we still have a long way to go before we can compete with the
complex behaviour achieved by a couple of grams of bug mush.

Re: Smallest system you've ever worked on?

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http://www.atip.org/public/atip.reports.95/atip95.87r.html (search on
"cockroach")
http://www.bbsonline.org/Preprints/Webb /
http://www.mindcreators.com /
http://www.iguana-robotics.com/people/tlewis/publications/rodney2.PDF
http://www.springerlink.com/index/3RRY22RUFE81767N.pdf
http://www.springerlink.com/link.asp?id=jhvjpb14dbjgb2yu

--
Guy Macon, Electronics Engineer & Project Manager for hire.
Remember Doc Brown from the _Back to the Future_ movies? Do you
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Re: Smallest system you've ever worked on?


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actually small neural net made of a bunch analog parts (12 or
something)

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funny you say that becouse the model I saw was simple as can be(<20
parts) yet fully operational



Pozdrawiam.
--
RusH   //
 http://pulse.pdi.net/~rush/qv30 /
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Re: Smallest system you've ever worked on?
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I think you are missing the point.  In those days, when we
discovered a faulty dip chip, we placed it on the floor and
executed it a la cockroach, with a ceremonial stomp.  This
prevented bean counters salvaging those valuable chips.

--
A: Because it fouls the order in which people normally read text.
Q: Why is top-posting such a bad thing?
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