 Later, in an attempt at diversification, ROLM themselves branched off into energy management by buying a company producing an early version of such a system and the telecom industry by designing the CBX, internally running a 1603 computer.It quickly outsold AT&T, who at the time had not come out with a digital PBX, and became #2 behind the Nortel SL-1 switch by 1980.At one point, ROLM was poised to overtake Nortel as the leader in PBX sales in North America.