British Telecommunications Plc was considering a plan to follow France Telecom into cheapo cheapo mass market Minitel terminals for directory inquiries and Prestel viewdata as long ago as May 1986, and as of this week it was still considering. But it has decided to go ahead with the other electronic telephone directory plan, the one that will enable businesses to look up telephone numbers over a computer link without the need to trouble the operator. Telecom is going to its existing supplier of directory systems, Computer Consoles Inc, for the kit, giving the Waltham, Massachusetts company a $16m contract. STC Plc installed the earlier Computer Consoles directory computer systems.