999, and it sat on the shelf for several years waiting for an opportunity to sell without a tariff [13]. The Computer II transition allowed the embedded base of older PBXs to remain under BOC tariff for an additional year. But the BOCs were by then rather distracted. The Modified Final Judg- ment (MFJ), divesting AT&T of the BOCs, had been arrived at after Computer II was passed but before it had taken full effect. The 1982 settlement of the long-running United States vs. Western Electric case took effect on January 1, 1984, and transferred all of the embedded terminal equipment to AT&T, while giving customers an opportunity to purchase it. The Regional Bell Operating Companies (RBOCs), in becoming separate companies in 1984, collectively kept the Bell trademark; ABI was renamed AT&T Information Systems. The RBOCs were allowed to sell CPE through their own fully separate subsidiaries, but they were starting from scratch. The RBOCs had lost their entire embedded PBX base to AT&T in the divestiture, but they did not lose all of their enterprise customers. In particular, they retained Centrex service, a PBX-type service delivered using central office facilities. Centrex had been the Bell System's flagship offering for large business since the 1960s; it allowed the features of large central office switches to be used for desktop phones. During the late 1970s, after Dimension's release, AT&T had tried to phase out Centrex via an "Installed Base Migration" [14] strategy. The BOCs had requested Cen- trex rate hikes in most states, succeeding in some. Suddenly, once the terms of divestiture had been announced, the BOCs realized that they lost their PBX base but kept Centrex, [15] SO their marketing strategy underwent a 180-degree turn. Centrex was revived and again became a flagship product. The Great Telecom Meltdown AT&T was only required to maintain existing rates for the embedded base for a brief transitional period. Some of the older, electromechanical systems were costly to maintain, so, to state it politely, AT&T 