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Re: [cosmacelf] Re: CDP1806ACE - ISA Standard committee

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  • David Keith
    Lee, The ABC was amazing for it s time. They did not get credit for being the first electronic computer until much later.  I have attached two circuit diagram
    Message 1 of 25 , Apr 14, 2013
    Lee,

    The ABC was amazing for it's time. They did not get credit for being the first electronic computer until much later.  I have attached two circuit diagram which I am not following exactly for my PCB layout.  I'm trying to do it with one VCC source and ground, so I may have to redo the PCB if my prototyping of the circuit fails.  Using a PCB is me just being lazy, I am not worried about an exact replica, someone else has already done that.  They do make 9 pin PCB tube sockets that hold the 12AU7 tubes about 3/8 inch above the board for cooling. However, I am concern with the thickness of the power supply leads, so they are both on both top & bottom layers. 

    --David Keith


    From: Lee Hart <leeahart@...>
    To: beloved_wind@...
    Sent: Sunday, April 14, 2013 1:03 AM
    Subject: Re: [cosmacelf] Re: CDP1806ACE - ISA Standard committee

    David Keith <beloved_wind@...> wrote:
    > Atanasoff–Berry Computer...

    This is amazing! I had never heard of this computer before. It is quite
    a remarkable invention, and way ahead of its time.

    The circuit board you showed: Where did you find the circuit diagrams of
    it? Are you building a reproduction of the ABC? Are you worried that
    PCBs weren't invented at the time, and in fact don't work all that well
    with tubes (because the heat of the tubes tends to damage the board and
    solder joints).

    --
    If we knew what we were doing, it wouldn't be called research, would it?
        -- Albert Einstein
    --
    Lee A. Hart, http://www.sunrise-ev.com/LeesEVs.htm




  • ajparent1
    ... the power as in plate voltage is low and in the milliamps area. the killer is the heater power as even at 12.6V that .15A per tube. Put ten of them on the
    Message 2 of 25 , Apr 14, 2013
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      --- In cosmacelf@yahoogroups.com, David Keith <beloved_wind@...> wrote:
      >
      > Lee,
      >
      >
      > The ABC was amazing for it's time. They did not get credit for being the first electronic computer until much later.  I have attached two circuit diagram which I am not following exactly for my PCB layout.  I'm trying to do it with one VCC source and ground, so I may have to redo the PCB if my prototyping of the circuit fails.  Using a PCB is me just being lazy, I am not worried about an exact replica, someone else has already done that.  They do make 9 pin PCB tube sockets that hold the 12AU7 tubes about 3/8 inch above the board for cooling. However, I am concern with the thickness of the power supply leads, so they are both on both top & bottom layers. 
      >
      >

      the power as in plate voltage is low and in the milliamps area.

      the killer is the heater power as even at 12.6V that .15A per tube.
      Put ten of them on the board and the lines need to be large enough for 1.5A. G10 board will tolerate the heat fine with good airflow.

      Cooling, fans are a great idea. you want to remove the heat as
      tubes themselves were fairly reliable but the heat could cook the local electronics (caps, resistors, and the like.) Orienting the board so the tubes are horizontal and the board vertical with good airflow upward (fan forced will help) can mtigate the heat things.
      build strong (use 2W resistor where 1W will work).

      If you have never worked with tubes, two things running them at 12.3V
      (tightly regulated) will greatly increase life especially if you bring them up slowly. Power cycling them tends to kill the heater.

      The other item is they do not like to be sitting at cutoff for long periods of time (cumulative days) as that poisons the cathode and emission goes down. There were special variants that were more tolerant of that.

      Doing a functional tube computer in this day is very possible.
      I understand a British group rebuilt and flat out made a copy of
      one of the code breaking machines (tubes).

      Allison



      > --David Keith
      >
      >
      >
      > ________________________________
      > From: Lee Hart <leeahart@...>
      > To: beloved_wind@...
      > Sent: Sunday, April 14, 2013 1:03 AM
      > Subject: Re: [cosmacelf] Re: CDP1806ACE - ISA Standard committee
      >
      >
      > David Keith <beloved_wind@...> wrote:
      > > Atanasoffâ€"Berry Computer...
      >
      > This is amazing! I had never heard of this computer before. It is quite
      > a remarkable invention, and way ahead of its time.
      >
      > The circuit board you showed: Where did you find the circuit diagrams of
      > it? Are you building a reproduction of the ABC? Are you worried that
      > PCBs weren't invented at the time, and in fact
      > don't work all that well
      > with tubes (because the heat of the tubes tends to damage the board and
      > solder joints).
      >
      > --
      > If we knew what we were doing, it wouldn't be called research, would it?
      >     -- Albert Einstein
      > --
      > Lee A. Hart, http://www.sunrise-ev.com/LeesEVs.htm
      >
    • jdrose_8_bit
      ... What are the differences between regular 2N2222 transistors and Field Effect transistors when implementing logic gates?
      Message 3 of 25 , Apr 17, 2013
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        > --- In cosmacelf@yahoogroups.com, David Keith
        >
        > I proposed the ISA committee so we as a group of 1802
        > assembler programmers can have a common future version to use and share.
        >
        > There are many ways to implement it, and several have already
        > been done by this group. I believe even Lee suggested implementing an
        > 1802 using fet transistors :-) a month or so back.
        >

        What are the differences between "regular" 2N2222 transistors and Field Effect transistors when implementing logic gates?
      • Lee Hart
        ... Quite a bit! Bipolar transistors are current-controlled; a current into the base (at negligible voltage) turns them on. FETs (including MOSFETs) are
        Message 4 of 25 , Apr 17, 2013
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          On 4/17/2013 8:14 PM, jdrose_8_bit wrote:
          >
          >> --- In cosmacelf@yahoogroups.com, David Keith
          >>
          >> I proposed the ISA committee so we as a group of 1802
          >> assembler programmers can have a common future version to use and share.
          >>
          >> There are many ways to implement it, and several have already
          >> been done by this group. I believe even Lee suggested implementing an
          >> 1802 using fet transistors :-) a month or so back.
          >>
          >
          > What are the differences between "regular" 2N2222 transistors and Field Effect transistors when implementing logic gates?

          Quite a bit! Bipolar transistors are current-controlled; a current into
          the base (at negligible voltage) turns them on. FETs (including MOSFETs)
          are voltage-controlled; a voltage into the gate (at negligible current)
          turns them on.

          You can built the same sort of circuits with either type, but the
          details of the circuit are quite different. Compare the internal
          schematic for a bipolar gate (7400 etc.) which is built with bipolar
          transistors, to that of a CMOS gate (4011 etc. built with MOSFETs. (The
          internal circuits are on the older data sheets.)

          If you wanted to build an 1802 from individual transistors, n-channel
          and p-channel MOSFETs would work with exactly the same circuits used in
          the 1802. The MOSFETs would cost you around 5-10 cents each.

          If you wanted to build an 1802 with bipolar transistors, you would have
          to replace each type of gate (inverter, NAND, NOR, flip-flop, etc.) with
          its equivalent bipolar circuit. It would wind up requiring more
          transistors and be faster; but use more power. Bipolar transistors are
          3-5 cents each, but you'd need more of them so the price probably comes
          out about the same.

          Either way, it would be a major project; like building a model Eiffel
          tower out of toothpicks. :-)

          --
          If you would not be forgotten
          When your body's dead and rotten
          Then write of great deeds worth the reading
          Or do these great deeds, worth repeating.
          -- Ben Franklin, from Poor Richard's Almanac
          --
          Lee A. Hart, http://www.sunrise-ev.com/LeesEVs.htm
        • David Keith
          A couple months ago I was recovering from double knee replacements (6 weeks apart) I had a lot of time on my hands that I could not work, I have been doing a
          Message 5 of 25 , Apr 17, 2013
          A couple months ago I was recovering from double knee replacements (6 weeks apart) I had a lot of time on my hands that I could not work,  I have been doing a lot experimenting with Diode Transistor Logic for a while now, so I decided to design a PCB and have some madeDTL is much easier and cost effective than a pure transistor circuit.  I decided to redesign an IBM SMS card using today's discreet components LOL.(I was on some very good drugs)  The original only SMS card I have contained 6 NAND circuits, while my new design uses 48 AOI (and-or-invert) gates (I prefer AOIs because I can design much tighter logic, with much less transistors). I have attached several pictures, of comparing the SMS basic form to my AOI board.  With another with a card almost populated, The last is the layout showing a 1 bit-slice CPU with 8 registers, full functional ALU (74181 equivalent), and data register to memory interface.  Overall it was just something to do that was not work related.  I plan to populate a board a month to get an 8-bit CPU/ALU core.

          --David Keith


          From: Lee Hart <leeahart@...>

          On 4/17/2013 8:14 PM, jdrose_8_bit wrote:
          >
          >> --- In cosmacelf@yahoogroups.com, David Keith
          >>
          >>  I proposed the ISA committee so we as a group of 1802
          >> assembler programmers can have a common future version to use and share.
          >>
          >>  There are many ways to implement it, and several have already
          >> been done by this group. I believe even Lee suggested implementing an
          >> 1802 using fet transistors :-)  a month or so back.

          >> What are the differences between "regular" 2N2222 transistors and Field Effect transistors when implementing logic gates?

          >You can built the same sort of circuits with either type, but the
          >details of the circuit are quite different. Compare the internal
          >schematic for a bipolar gate (7400 etc.) which is built with bipolar
          >transistors, to that of a CMOS gate (4011 etc. built with MOSFETs. (The
          >internal circuits are on the older data sheets.)

          >If you wanted to build an 1802 from individual transistors, n-channel
          >and p-channel MOSFETs would work with exactly the same circuits used in
          >the 1802. The MOSFETs would cost you around 5-10 cents each.

          >If you wanted to build an 1802 with bipolar transistors, you would have
          >to replace each type of gate (inverter, NAND, NOR, flip-flop, etc.) with
          >its equivalent bipolar circuit. It would wind up requiring more
          >transistors and be faster; but use more power. Bipolar transistors are
          >3-5 cents each, but you'd need more of them so the price probably comes
          >out about the same.


          --
        • bill rowe
          Keith: what does the card do? To: cosmacelf@yahoogroups.com From: beloved_wind@yahoo.com Date: Wed, 17 Apr 2013 21:19:46 -0700 Subject: Re: [cosmacelf] Re:
          Message 6 of 25 , Apr 18, 2013
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            Keith: what does the card do?


            To: cosmacelf@yahoogroups.com
            From: beloved_wind@...
            Date: Wed, 17 Apr 2013 21:19:46 -0700
            Subject: Re: [cosmacelf] Re: 2N2222 ++ 1N914 DTL (off topic) [4 Attachments]

             
            [Attachment(s) from David Keith included below]
            A couple months ago I was recovering from double knee replacements (6 weeks apart) I had a lot of time on my hands that I could not work,  I have been doing a lot experimenting with Diode Transistor Logic for a while now, so I decided to design a PCB and have some madeDTL is much easier and cost effective than a pure transistor circuit.  I decided to redesign an IBM SMS card using today's discreet components LOL.(I was on some very good drugs)  The original only SMS card I have contained 6 NAND circuits, while my new design uses 48 AOI (and-or-invert) gates (I prefer AOIs because I can design much tighter logic, with much less transistors). I have attached several pictures, of comparing the SMS basic form to my AOI board.  With another with a card almost populated, The last is the layout showing a 1 bit-slice CPU with 8 registers, full functional ALU (74181 equivalent), and data register to memory interface.  Overall it was just something to do that was not work related.  I plan to populate a board a month to get an 8-bit CPU/ALU core.

            --David Keith


            From: Lee Hart <leeahart@...>

            On 4/17/2013 8:14 PM, jdrose_8_bit wrote:
            >
            >> --- In cosmacelf@yahoogroups.com, David Keith
            >>
            >>  I proposed the ISA committee so we as a group of 1802
            >> assembler programmers can have a common future version to use and share.
            >>
            >>  There are many ways to implement it, and several have already
            >> been done by this group. I believe even Lee suggested implementing an
            >> 1802 using fet transistors :-)  a month or so back.

            >> What are the differences between "regular" 2N2222 transistors and Field Effect transistors when implementing logic gates?

            >You can built the same sort of circuits with either type, but the
            >details of the circuit are quite different. Compare the internal
            >schematic for a bipolar gate (7400 etc.) which is built with bipolar
            >transistors, to that of a CMOS gate (4011 etc. built with MOSFETs. (The
            >internal circuits are on the older data sheets.)

            >If you wanted to build an 1802 from individual transistors, n-channel
            >and p-channel MOSFETs would work with exactly the same circuits used in
            >the 1802. The MOSFETs would cost you around 5-10 cents each.

            >If you wanted to build an 1802 with bipolar transistors, you would have
            >to replace each type of gate (inverter, NAND, NOR, flip-flop, etc.) with
            >its equivalent bipolar circuit. It would wind up requiring more
            >transistors and be faster; but use more power. Bipolar transistors are
            >3-5 cents each, but you'd need more of them so the price probably comes
            >out about the same.


            --

          • jdrose_8_bit
            Thank you. Great explanation. I knew how bipolar transistors worked but FETs were a mystery to me.
            Message 7 of 25 , Apr 18, 2013
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              Thank you. Great explanation. I knew how bipolar transistors worked but FETs were a mystery to me.

              --- In cosmacelf@yahoogroups.com, Lee Hart <leeahart@...> wrote:

              > >
              > > What are the differences between "regular" 2N2222 transistors and Field Effect transistors when implementing logic gates?
              >
              > Quite a bit! Bipolar transistors are current-controlled; a current into
              > the base (at negligible voltage) turns them on. FETs (including MOSFETs)
              > are voltage-controlled; a voltage into the gate (at negligible current)
              > turns them on.
              >
              > You can built the same sort of circuits with either type, but the
              > details of the circuit are quite different. Compare the internal
              > schematic for a bipolar gate (7400 etc.) which is built with bipolar
              > transistors, to that of a CMOS gate (4011 etc. built with MOSFETs. (The
              > internal circuits are on the older data sheets.)
              >
              > If you wanted to build an 1802 from individual transistors, n-channel
              > and p-channel MOSFETs would work with exactly the same circuits used in
              > the 1802. The MOSFETs would cost you around 5-10 cents each.
              >
              > If you wanted to build an 1802 with bipolar transistors, you would have
              > to replace each type of gate (inverter, NAND, NOR, flip-flop, etc.) with
              > its equivalent bipolar circuit. It would wind up requiring more
              > transistors and be faster; but use more power. Bipolar transistors are
              > 3-5 cents each, but you'd need more of them so the price probably comes
              > out about the same.
              >
              > Either way, it would be a major project; like building a model Eiffel
              > tower out of toothpicks. :-)
              >
              >
              > Lee A. Hart, http://www.sunrise-ev.com/LeesEVs.htm
              >
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