caput vs read/write head

caput

noun

  • The head. 

  • A knob-like protuberance or capitulum. 

  • The top or superior part of a thing. 

  • The council or ruling body of the University of Cambridge prior to the constitution of 1856. 

read/write head

noun

  • A combination read head and write head 

How often have the words caput and read/write head occurred in a corpus of books? (source: Google Ngram Viewer )