What does the cryptic crossword clue "Old-fashioned computing aid to record sound of a cadence (9)" mean?

The definition is "Old-fashioned computing aid". The wordplay uses a homophone (sounds like). sounds like LOG A RHYTHM. The answer is LOGARITHM.

Old-fashioned computing aid to record sound of a cadence (9)

Times Cryptic #28785 | 14 Down | 2023-12-13 flower