Second hand info: (first hand in the Boston Phoenix (day unknown))

SPEED CUBING COMPETITION

Date: Saturday, July 25, 1981
Place: Jordan Marsh, Burlington, Massachusetts

Times:

1100-1500  3 minute qualifiers
1530-1800  Registration and Playoffs
1800-....  Finals

First prize is N hundred dollars, where N is about 5.

(Sorry for the lack of info, we got this over the phone in a
hurry.)