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SESK: Stuff Everyone Should Know · sesk.info/hame-gray-code

Which digital code allows only one bit to change between sequential code values?

Gray code changes just one bit at a time.

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  1. Gray code ✔
  2. Binary coded decimal
  3. Extended ASCII

Why: Counting in Gray code flips only a single bit per step. That avoids glitches where several bits change at slightly different moments.

Huh, didn't know that: Baudot uses 5 data bits per character, while ASCII uses 7 or 8 (E8D10).

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References

Answer: Gray code. Counting in Gray code flips only a single bit per step. That avoids glitches where several bits change at slightly different moments.

  1. NCVEC 2024-2028 Amateur Extra Question Pool, 4th Errata (Feb 4, 2026) ncvec.org/downloads/2024-2028%20Extra%20Class%20Question%20Pool%20and%20Syllabus%20Public%20Release%20with%204th%20Errata%20Feb%204%202026.pdf
    D. Gray code
    Checked 2026-10-11.

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