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Logic Analyzer/Oscilloscope

My Hewlett-Packard 1631D logic analyzer / digital oscilloscope arrived today: the finest 1985 technology that $35 can buy. I bought it dirt cheap from eBay in “as is” condition, but it seems to be working great! With this acquisition, I can proudly say that I’ve crossed the line from ordinary run-of-the-mill nerd to super-nerd.

Holy cow, there are a lot of buttons and wires on this thing. What’s a trigger? Where’s the manual? My head hurts just thinking about it.

After some time spent jabbing hesitantly at buttons, I finally managed to get a scope trace working. Here it is, showing the output of a 1 MHz clock oscillator. Mmmm, square wavy goodness!

HP 1631D

Read 10 comments and join the conversation 

10 Comments so far

  1. Matt - February 28th, 2009 1:57 am

    “I can proudly say that I’ve crossed the line from ordinary run-of-the-mill nerd to super-nerd.”

    Yes, yes you can! I’ve been browsing through this blog after hackaday linked to it, and I’m blown away at your skill and persistence on this project!

    You put supposed hardcore geeks like me to shame. Very well done!

  2. Metaforest - May 30th, 2009 10:56 pm


    I actually used to have one of those HPs on my desk when I was an SQA engineer for the Apple //gs project back in 1986 and 1987. That just took me on a Wayback Machine trip…. 😀 Thanks

  3. robert - February 28th, 2012 6:04 am

    just for 35$ a 1631D HP analyser really good deal
    but with pods ? for logical input ?


  4. Steve Chamberlin - February 28th, 2012 7:08 am

    Yes, it included three or four pods for state and timing inputs too. Not all of them had the wire/probe attachments, though, so I had to build my own.

  5. Anders Gustafsson - October 23rd, 2014 10:36 am

    I found that the crimp connectors used in car connectors work very well for the 1631D pods. Just crimp whatever wires you need and put some heat shrink tubing on and they will push right on the pins on the pods. Dunno what they are called, but I bought a whole bag at an outlet that sells car spareparts.

  6. Chris - August 17th, 2017 1:53 pm

    Hello I wondered if you had any information or pictures of the pod interface connectors that you made. I have just bought a HP1631D and need to make some pod connectors. Also wondered if you had the circuit diagram I have the service information but no circuit diagram. Any help or advice much appreciated. The link above is to my YouTube Channel I’m a big fan of test equipment.

    Best regards Chris

  7. Anders Gustafsson - August 18th, 2017 5:04 am
  8. Anders Gustafsson - August 18th, 2017 5:06 am

    Also see this “disk” that makes loading/storing settings easier:

  9. Chris - August 18th, 2017 3:08 pm

    That’s great many thanks for the information. That will be useful. My best regards Chris

  10. Anders Gustafsson - August 19th, 2017 8:00 am

    You are welcome!

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