4116 D Ram tester with schematics and code

After several requests I finally got around to finish documenting an old project from the fall 2017. The ancient computer in our Solid State Logic SL4064G+ console uses a lot of 4116 D Ram which are known to go bad. Therefor I needed a way to check which IC is bad when I see a graphic error on the SSL computer screen. I looked around on the internet and found this post on a project designing a D ram tester for a different kind of D ram. Based on this design a made a version for the 4116 type D ram and reused most of the arduino code.

Please let me know if you find any errors in these attachements, thanks!

UPDATE 3: Thanks to Sleepwalker3 again for making comments about another bug. I have uploaded af fixed version of the code ei. version 3.

UPDATE 2: Thanks to Rauno and Sleepwalker3 for making comments about a very seriously bug which meant only RAM address 0 was checked. I have uploaded af fixed version of the code ei. version 2.

UPDATE: The initial schematic had errors in the inverting circuit for the -5vdc. Sorry. Below is a link to the corrected rev2 version:

Download the rev2 schematic here: 4116_tester_schematic

Download the arduino version 2 code here:  4116_tester_ulh.ino

14 thoughts on “4116 D Ram tester with schematics and code

  1. Hi,

    it’s a beautiful project and I’d like to make it happen, but I’m not an arduino expert; please tell me which software should i download to program arduino nano? thank you so much


  2. Hello.
    First of all, I want to congratulate you on the 4116 memory tester you designed.
    I need to test 10 Chips 93422PC memories – SRAM 256×4 – 45 ns. Will it be possible to adapt your 4116 tester to this 93422PC – SRAM 256×4 – 45 ns? Sorry, but I don’t know anything about programming but I have experience in electronic assemblies. Regards

    Heitor Lima


    1. Dear Heitor Lima,
      as I see your chip has different implementation then the 4116. No multiplexed data expected on its data bus and even data input and output are different. You need a completely different implementation, both in software and hardware.

    1. Thanks Rauno. Yes you are right. I have edited the code and updated the post. Thanks a lot for letting me know!

    1. You are totally correct. Just checked and flashed the edited code to my hardware and it now detected an error on a 4116 ic which did not show up with the old code. I have edited the post. Thanks a lot.

  3. Well there’s been some more developments where some further problems with the DF code have been shown up, so you it would be worthwhile taking a look at that again.

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