AT&T Co is preparing a personal computer that doubles as a workgroup PABX able to handle up to 10 extensions or so for launch in the second quarter of this year. Called the PCX, the machine is an MS-DOS personal computer modified with plug-in line cards, and software that provides the main PABX functions such as call-forwarding and the ability to record all the traffic going through it. The computer may be from Olivetti, but is more likely to be built around the 80286 and 80386 boards that AT&T is buying OEM from Intel. The possibility for user programming of telephone functions and the fact that the machine should be able to double as a personal computer suggests that the PCX could open up a completely new market – but one likely to become crowded quite fast if the AT&T offering catches on.