Homebrew 8 1/2 Digit DIgital Voltmeter (DVM)
Hackaday: Homebrew Metrology The CERN Way.
[1]https://hackaday.com/2021/02/26/homebrew-metrology-the-cern-way/

   Jim Bell's note:. In 1974, one of my early electronics projects was to
   design and build a 4 1/2 Digit DVM, including a custom-designed printed
   circuit board that I laid out and etched.

   It used a MK5002 counter chip.

    https://www.datasheetarchive.com/?q=MK5002

References

   1. https://hackaday.com/2021/02/26/homebrew-metrology-the-cern-way/