How hard is to build a processor?

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It seems that “Google” engineer Bill Buzbee isn’t interested in
microprocessors that can be purchased in marked. There is more fun to
build own. Several years ago he built first “Magic-1” processors
, but now he makes its documentations widely available in his project
website.

http://www.embedds.com/how-hard-is-to-build-a-processor /


Cheers Don...


--
Don McKenzie

Site Map:            http://www.dontronics.com/sitemap
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Re: How hard is to build a processor?



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Why not ?
Someone should be keeping the old craft alive. Good on him !
You could ask 'why build museums' ?
I think you agree.





Re: How hard is to build a processor?



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Thanks, Don.  I absolutely LOVE doing this kind of thing.  It
should be required work for anyone in embedded programming,
at least.  35 years ago I tried my hand at it and failed to
get much useful.  It wasn't until I later got access to a
logic simulator that I was finally able to complete a
successful processor design with 7400 logic, not using the
74181 ALU by the way, though I never built what seemed to
work so well.  Later, I picked up a Xilinx 4000 series demo
board and, for the very first time, learned to write VHDL and
finally coded up my first processor that worked!!!  (I didn't
do the floorplanning by hand -- way over my head at the
time.)

I learned so much doing this, though.

Anyway, thanks for the link!!

Jon

Re: How hard is to build a processor?


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...


That reminds me that there are some excellent course videos by David
Culler of Berkeley showing how to build a CPU from logic gates. A bit
of searching for his webcasts for course 61CL Fall 2009 in H.264 video
should bring them up.

I had no idea until working through the lectures that *I* could build
a CPU using components I already knew about. As part of the course he
shows how to do so by working up from logic gates.

James

Re: How hard is to build a processor?


  wibbled on Friday 26 February 2010 10:52

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I knew a chap (York University Computing Services) who claimed to have a
mate who built an elementary CPU from fruit machine relays[1]. Occupied a
bit of board about one square yard. He lost interest in building RAM from
more relays, so wedged a 1k RAM chip with suitable interfacing on the side.
Ran at about 1 IPS apparently...

[1] he got a box load from a surplus store, old stripped out ones. Had an
unusual contact configuration that made them quite suitable.

--
Tim Watts

Managers, politicians and environmentalists: Nature's carbon buffer.


Re: How hard is to build a processor?



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Reminds me of the pdp11 look alike I worked on back in the early 70's... few
hundred ttl chips , 64 bit diode matrix microcode, 8K ferrite sotore driven
by loys of monostables to get the timing right....
I was used to poser some of the very first CNC machines in the UK- Herbert
BatchMAtic and in Germany - Boehringer Vxxx series lathes.
Those were the happy days......



Re: How hard is to build a processor?

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Back in '74 Elektor published a design of a computer built with TTL-logic.
They really made it work though I doubt any subscriber built it too.

petrus bitbyter



Re: How hard is to build a processor?
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Back in '73 I worked on a 16 bit mini computer built entirely out of
TTL, complete with a row of toggle switches on the front panel so you
could enter machine code by hand. It had a paper tape reader and along
with a paper tape punch you could use the two pass assembler - that's a
lot of paper.

Cheers

ian

Re: How hard is to build a processor?

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@Ian, who did you work for in 73 ???



Re: How hard is to build a processor?


Cool!  Over on alt.folklore.computers there was a recent thread about
projects implementing old CPUs with an FPGA.  Very neat stuff out there
for the retrocomputing world.
--
As we enjoy great advantages from the inventions of others, we should
be glad of an opportunity to serve others by any invention of ours;
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Re: How hard is to build a processor?




Don McKenzie wrote:

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It is a lost art. In the 70's I taught a course that students built
a small computer out of lab modules of TTL chip's. My first
personal computer was micro coded PDP-8 hand built.

Ram was 1K (bits) parts on a wirewrap board.

Walter..



Re: How hard is to build a processor?


On Fri, 26 Feb 2010 10:10:55 -0500, Walter Banks
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Oh, my, Walter.  That would have been a wonderful class to
have taken.  I only wish...

Jon

Re: How hard is to build a processor?


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In 1961 a colleague told me of a machine in a lab at Cornell named20%
CADET, which reputedly stood for "can't add, doesn't even try".  But it20%
was a universal (Turing) machine.  Most everyone has stood on the20%
shoulders of software to extend behavior.  In another sense, cpu20%
development has also stood on the shoulders of software arts, for needs20%
drive real engineering, not possibilities, and software disciplines20%
provide the languages for expressing these needs.

Each to his own.  Some yearn to create a theory, some to create a20%
bridge, some to create an impression.  I still ponder the structure of a =

(programmable) computer of light and heavy marbles, gates, and a bunch20%
of elevators.

-- Bill Cooke

Re: How hard is to build a processor?



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IBM 1620.  See http://en.wikipedia.org/wiki/IBM_1620

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Another fun project!
--
As we enjoy great advantages from the inventions of others, we should
be glad of an opportunity to serve others by any invention of ours;
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Re: How hard is to build a processor?


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 processors
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Hah!  My leg's been pulled.  and to think I'd just finished a year on20%
1401, 705 code!  I'd thought 'cadet' was a lab project, not a for-real20%
machine.  I've even read a 1620 manual, but never got to write for one.

-- Bill

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Re: How hard is to build a processor?


On Fri, 26 Feb 2010 14:18:14 -0700, Bill Cooke

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I can remember hearing that phrase from time to time when I
worked on the 1620.  It was a fun machine.  I used to swap
out the colored bezels on the control panel just to tease.

Jon

Re: How hard is to build a processor?


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I was working at a small shop that had a hand-me-down 1620.  They had a simple
Fortran compiler, "PDQ Fortran", but it lacked some features they wanted.  On my
own, I wrote a disassembler for the 1620, disassembled the compiler, studied the
code, figured out how to save some code space (memory was limited), then add
some features, basically enhanced write commands and formatting, all with no
external documentation.  When the code was almost ready I was so excited I
couldn't sleep, so went into work at 4 AM or such and got it working.  Fun days!

--
Thad

Re: How hard is to build a processor?




Bill Cooke wrote:

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The IBM 1620 was the first computer I used. It had
some interesting features, a BCD machine with variable length
data words.

I ran a fibonacci series on it to 2000 terms it took 18 hours.

A lot of neat things could be done with the math tables which
could be set at run time. The math tables were also the target
some elaborate pranks in IBM 1620 labs

It was also the first computer that I wrote a compiler for. I
have a lot of good memories of the 1620.

That was a long time ago.

Regards,

Walter..
--
Walter Banks
Byte Craft Limited
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Re: How hard is to build a processor?


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I wonder how many kiddies these days actually own a wirewrap tool?

Re: How hard is to build a processor?




Don McKenzie wrote:

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It is trivial to build a processor. This type of project is a semester20%
work for a student. It is hard to make commercially viable processor,20%
though.

VLV


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