cmoore@brl.mil (VLD/VMB) (03/01/90)
These New York Times articles refer to the then-new 1+ requirement in front of area code (year is 1980): Sept. 23, p. 1 col. 4 Nov. 22, p. 26 col. 1 Nov. 24, part II, p. 3 col. 4 The Sept. 23 (1980) article said there were 650 (sic) prefixes in use in NYC (I believe there are only 640 NNX prefixes). All 3 articles said that, according to New York Telephone, the change would make 152 new prefixes available, for 1.5 million new phone numbers, a 25-year supply. (Recall that this was only 4 years before the 212/718 split.)