Re: My Electric PC Dream

In alt.engineering.electrical The Great Attractor wrote: | On 13 May 2007 14:24:43 GMT, snipped-for-privacy@ipal.net wrote: | |>I suggest you would spend your time better by building a computer that |>runs entirely on photons from light. Be sure it can handle a wide range |>of photon energy levels (wavelengths). If you can fabricate picogates |>that can operate entirely by holding a single photon in state and switch |>the next photon based on a held photon, then you may well have achieved |>the elusive 100% energy efficiency. Holding a photon would be the big |>trick (they prefer to move very fast, so you will have to fool it and |>run it around in a circle or bounce it back and forth). | | | Even a 4 bit light computer has the potential to be far faster than | anything we currently use.

There is also such a thing as a 1-bit computer, where the computational functions can be performed on various data sizes streamed in serially. Two 1-bit-wide data streams can be added as they arrive if they come in little-endian order. Many other functions of a CPU can still be made to work on serialized 1-bit-wide data, as well. Then the parts count and die space can be applied to making a faster serial rate instead of just raw parallel bits. We see a lot of technology moving this way already, such as RAMBUS, SATA, and PCI-Express.

I envision a future computer using things like the different refractive index at different wavelengths to serialize and deserialize data within a CPU.

| There are physical devices required that make this goal very elusive, | however. You iterate one such obstacle.

Indeed.

Once we get to the point where we can assemble material by precise placement of single atoms in 3 dimensions, I think we'll find ways to construct what it takes to accomplish single photon level gates and other circuits.

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|---------------------------------------/----------------------------------|
| Phil Howard KA9WGN (ka9wgn.ham.org)  /  Do not send to the address below |
| first name lower case at ipal.net   /  spamtrap-2007-05-13-2119@ipal.net |
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My dream PC is at least 32-bit.

Then, as stated earlier... you really don't get it.

In alt.engineering.electrical Radium wrote: | On May 13, 2:58 pm, The Great Attractor | wrote: | |> Even a 4 bit light computer has the potential to be far faster than |> anything we currently use. | | My dream PC is at least 32-bit.

I guess a 256-bit CPU architecture would comply with that dream.

-- |---------------------------------------/----------------------------------| | Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below | | first name lower case at ipal.net / snipped-for-privacy@ipal.net | |------------------------------------/-------------------------------------|

In the early to mid '60s Don Hitt of IBM's Systems Development Division, a field engineer turned mainframe designer and my first mentor, built in his Poughkeepsie basement exactly the computer who's architecture you suggest. It used a magnetic drum memory and a glass acoustic delay line from one of IBM's office products.

[begin reminiscence]

A couple of years later Don and Bob Wasserman designed and built the first microprocessor so far as I can tell: a 4-bit ECL computer with

4K ram. While it was not a a single chip device it had all of the elements necessary to call it a microprocessor. It was also the first and most reduced RISC I've ever heard of. It had four instructions and no arithmetic logic unit, just an accumulator it could load, store and conditionally branch on being zero. The fourth instruction was a branch and link. Using table lookup, storing into the instruction stream and subroutines for ALU operations it was programmed first as a scientific desk calculator driving an oscilloscope as a decimal digit display device.

It was a between-project bit of fun for these guys but with serious intent. They incorporated it in our next project, the System/370 Model 158, as its minimal-core maintenance processor to diagnose hardware failures in the mainframe and tell field engineers what logic card to replace. I did a large part of that programming.

It was also used as the first in-house floppy drive writer. The first field use of a floppy was for storing the diagnostic programs that the little processor executed in diagnosing the mainframe. As a floppy writer it was channel attached to a System/360.

You wouldn't believe the number and variety of mechanical designs tried out before the final 8" oxide coated mylar disk in an envelope design that went to the field as a floppy disk.

[end reminiscence]

Thanks for triggering that memory. :-)

Bob

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"Things should be described as simply as possible, but no simpler."

                                             A. Einstein