back to article Pong, anyone? How about Pong on a vintage oscilloscope?

Warning: there's no real IT angle in a chap hacking a venerable Tektronix Type 422 oscilloscope to play Pong. It's just fun. The Frankensteinian machine is the brainchild of Glen Kleinschmidt over at the electronic hobbyist site EEVBlog. There's no “take the easy way” about Kleinschmidt's work: sure, it might be easy to …

  1. AndyS

    I once built a circuit to manually control an early 1990s Toyota automatic gearbox, using 4000 series logic gates. It was an interesting project. Lots of admiration for going a step further and using the bare transistors to do something like this though!

    ps - in the end I decided that the ECU was better at changing gears than me, so I removed it all again.

  2. herman Silver badge

    Gaddammit... the only way to top that, would be by building a Pong game from thermionic valves.

    1. Anonymous Coward

      Re : the only way to top that...

      Or building an entire processor out of discrete transistors...

    2. Mage Silver badge

      Thermionic Pong

      Probably work out at about $400 using the small Russian 6.3V indirect double triodes similar spec to ECC82. Maybe $800 using Russian rod Pentodes such as 1j24b (much cooler as filament is about 12mA at 1.2V), but you need twice as many.

      You can get NOS Russian tubes/valves made as late as 1980s on eBay from Eastern European or Russia for as low as $1.50 each in bulk.

      So totally doable. I remember in 1970s in college that someone made a "pong" using a matrix of red LEDs as display and simple 4000 series logic. You can make a flip flop with two valves and gates using resistor capacitor inputs need one valve.

      The difficulty is that grids can't couple direct to anodes. But example gate circuits are on the internet.

      The Rod Pentode, though, can be switched at high voltage on screen grid, so DC coupling using the g1 only for bias is possible, then the HT can be about +45V.

    3. Captain DaFt

      "the only way to top that, would be by building a Pong game from thermionic valves."

      How about a more sophisticated tennis game, using relays?

      Tennis for two, built in 1958!

    4. DropBear

      Not necessarily... you could always implement it on proper hardware, with the paddles actuated by servos, the ball on a Cartesian frame, etc (actually, I seem to recall at least one such a build)...

  3. Harry the Bastard

    the 422 is ok, but i lurved my 453

    back in the 80's i built a digital storage add-on for it

    it was a tragic day when i let it go, sniffle

  4. Anonymous Coward
    Anonymous Coward

    "Gaddammit... the only way to top that, would be by building a Pong game from thermionic valves."

    It would have been affordable in the 60s and even the 70s, when people were giving away box loads of EF50s and the like, but very expensive now. Sadly, I have only a couple of EF91s left in working order.

    1. A K Stiles


      Just a quick reminder that the National Museum of Computing at Bletchley Park are always on the lookout for working valves to keep their rebuilt Tunny / Bombe / Bedstead going a bit longer.

    2. Mage Silver badge

      affordable in the 60s and even the 70s

      Actually, taking account of inflation, it's much cheaper now, using Chinese and Russian NOS.

      I don't remember these boxes of free valves. It's true that war surplus in 1950s and 1960s was cheaper than new valves. My ex WWII wireless sets used up a lot of pocket money in the latter 1960s.

      As did photocopies of the R&TVS from Central Library to repair valve TVs and valve Radios. One paid a small fee to get valves tested rather than wasting money on new ones for repairs.

      1. jake Silver badge

        Re: affordable in the 60s and even the 70s

        One didn't pay a small fee to get tubes tested. One tested them ones self (if so inclined) or took them to the nearest hardware store (I used Coast to Coast (or Radio Shack, back when it was just that)) and plugged them into the test console for free ...

        I still have a 1950s Philco radio to listen to SF Giants baseball on, and my audio gear (home and stage) is powered by 1960s McIntosh.

        Note it's "tube", not "valve". Or do you say "electron valve", "vacuum valve" and "cathode ray valve"?

        1. Anonymous Coward
          Anonymous Coward

          Re: affordable in the 60s and even the 70s

          "Valve" is the British term for the American phrase "Vacuum Tube". They are correct in their usage.

  5. Stuart Halliday
    Thumb Up


  6. Tom 64


    Big respect for all that solder work... I'd give up by joint 20.

    I wonder what is the minimum amount of transistors you could get away with building a game of pong from.

    1. phuzz Silver badge

      Re: Awesome

      I'm pretty sure you can do it with zero, but the user interface is slightly archaic.

      1. TRT Silver badge

        Re: Awesome

        Close, but I don't think these sisters are trans.

      2. allthecoolshortnamesweretaken
        1. Message From A Self-Destructing Turnip

          Re: Awesome

          I think most would have given up and gone to find something to eat long before joint 20. You passing​ that?...

  7. Steve Crook


    This sort of thing is amusing, interesting, inspiring. But I just feel inadequate, uneducated, ill informed. A bit like a taster version of the Total Perspective Vortex.

    1. Chemical Bob

      Re: Enough!

      "inadequate, uneducated, ill informed."

      You are qualified to run for President.

  8. AceRimmer1980


  9. TRT Silver badge

    That's so awesome!

    But the thought of all that soldering...

    Does anyone have a SPICE file so I can run it as a simulation, please?

  10. John Brown (no body) Silver badge

    Kudos for the effort....

    ....but wasn't there one built this way originally? Long before Atari "invented" Pong.

    1. Nick Ryan Silver badge

      Re: Kudos for the effort....

      AFAIK Pong (the game with the name) was invented, or populised, by Atari. There were many earlier computer games but none called Pong.

    2. Dave 32

      Re: Kudos for the effort....

      <sigh> This makes me feel old...

      There was a version of a pong circuit which was published in, I think, Popular Electronics magazine a little over 40 years ago (I seem to remember a rather dark cover with a green image.). I remember saving up my lunch money to buy a copy. I never built the device, but it was interesting to study the schematic.


      P.S. I'll get my coat. It's the one with the punched cards in the pocket.

      1. Blue Pumpkin

        Re: Kudos for the effort....

        This is the article you are looking for

        page 35 onwards :-)

        Somebody has done a sterling job of OCR-ing the whole lot into PDFs for your joy and delectation.

    3. bombastic bob Silver badge

      Re: Kudos for the effort....

      you have to REALLY want to do it "that way" to put in that kind of effort.

      It reminds me of a binary "computer" my 3rd grade teacher's son built in the 1960's (ca 1968), using discrete components. It could add 2 binary numbers, had light bulbs to indicate the binary result, and switches to enter the numbers. I was confused by difficulty of the process of entering the numbers, like "I have to do MORE math just to enter the values I'm adding, than the actual calculation". Oh, and it could SUBTRACT, too.

      Now that I think of it, he must've had a lot of work to do, building all of those gates and half-adders out of discrete components...

      (but there might've been RTL gates available back then, not like that would really be that much easier)

      1. DJSpuddyLizard

        Re: Kudos for the effort....

        Then there was this:

        That's the thing that actually took my interest in electronics and made me want to try programming.

        When I later found that I could completely understand a BASIC listing for a TRS-80 Nim game, then I was hooked.

      2. Captain DaFt

        Re: Kudos for the effort....

        "It reminds me of a binary "computer" my 3rd grade teacher's son built in the 1960's"

        This one?

  11. bobbear

    Discrete transistors & a 'scope! Wow! I can't beat that either. I saw pong for the first time on a machine in a pub in about 1970 or thereabouts and went home to think about it and eventually made a version using 7400 series texas instruments ttl logic chips. It was in a nice wooden box and used slider pots for the bat controllers. It's probaby still up in the loft somewhere... I bet loads of people did exactly the same.. It was a great way to learn about logic functions.

  12. vir

    For The Lazy Among Us

    You can just grab a HP54600B and play Tetris:

  13. John Smith 19 Gold badge

    Highly entertaining.

    It's the sheer "love of the game" aspect that's impressive.

    Various magazines had TV games in the 70's and 80's. The discrete logic ones probably taught the builders a massive amount about what you can and cannot do with TTL although later on they seemed to have been built around General Instruments games chips. Not sure if they were custom logic, gate array or can what we would now call a pre programmed PIC inside them.

    I'm guessing such games are close to the point where you could just build a TTL processor using LS '181 ALU's (no idea how expensive they were in the 70's) and write an instruction sequence (or "program" as I call it ) to simulate such a game.

    1. Anonymous Coward
      Anonymous Coward

      Re: Highly entertaining.

      I'll say! What a great build! It reminded me of my various Pong systems I collected over the Internet back in the late 1980s. I have several Pong units in various conditions, but also some of the even earlier TV paddle games from Magnavox:

      My oldest Odyssey is not pictured, so I'm thinking it might be a Odyssey 400. Now I have to search for it and check which will be a fine task for a rainy Saturday. I also have an Odyssey 3000. That one needs some work on the paddle controllers, although otherwise they are of sturdy construction. Who needs a tech museum when you have a garage full of old tech from the olden days?

  14. Herby

    On building Pong...

    My experience was with a single chip (plus video modulator) game of pong. You hooked up a couple of potentiometers to the game and they controlled the position of the paddle. It worked quite well. One of my friends made the mistake of trying to hook up "audio taper" (logarithmic curve) to the game (instead of "linear taper"). The thing worked OK, but you had to understand that the movement was in the last tenth or so of the rotation.

    Fun in the early 70's. You needed to be there!

  15. Gareth 7

    How about Quake ?

    1. John Smith 19 Gold badge
      Thumb Up

      Quake on an Oscilloscope.

      Wow, converting a 'scope into a vector scan display is quite remarkable.

      1. This post has been deleted by its author

      2. Anonymous Coward

        Re: Quake on an Oscilloscope.

        I've seen the same trick done with a disco laser, playing Pong on the side of the Garden Gate pub in Aldershot (kit supplied by Video Game Carnival).

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