I might dig out my norse etymology dictionary and a magnifying glass and try to trace it back further.
-- From Etymonline:
Teeter:
1843, "to seesaw," alteration of Middle English titter "move unsteadily," probably from a Scandinavian source akin to Old Norse titra "to shake, shiver, totter, tremble," from Proto-Germanic *ti-tra- (source also of German zittern "to tremble"). Meaning "move unsteadily, be on the edge of imbalance" is from 1844.
[...]Noun teeter-totter "see-saw" is attested from 1871 (earlier simply teeter, 1855, and titter-totter in same sense is from *1520s*). Totter (n.) "board swing" is recorded from late 14c.;
Source: am Dutch, would never pronounce titter as dither even with a bad accent. More likely the other way around actually.
Conference rooms and lab rooms often had amusing names — as I am sure is true at other companies besides Apple. "Rock" and "Hard Place" were two neighboring conference rooms.
Another floor as I recall had conference rooms named with oxymorons, "Military Intelligence", "Jumbo Shrimp" and — was it "Lawrence Expressway"? — something funny to Bay Area residents anyway.
> Etymology
> …[O]ne of the earliest [applications] of dither came in World War II. Airplane bombers used mechanical computers to perform navigation and bomb trajectory calculations. Curiously, these computers (boxes filled with hundreds of gears and cogs) performed more accurately when flying on board the aircraft, and less well on ground. Engineers realized that the vibration from the aircraft reduced the error from sticky moving parts. Instead of moving in short jerks, they moved more continuously. Small vibrating motors were built into the computers, and their vibration was called dither from the Middle English verb "didderen," meaning "to tremble." Today, when you tap a mechanical meter to increase its accuracy, you are applying dither, and modern dictionaries define dither as a highly nervous, confused, or agitated state. In minute quantities, dither successfully makes a digitization system a little more analog in the good sense of the word.