text: Early minicomputer-based typesetting software introduced in the 1970s and early 1980s such as Datalogics Pager , Penta , Miles 33 , Xyvision , troff from Bell Labs , and IBM 's Script product with CRT terminals , were better able to drive these electro-mechanical devices , and used text markup languages to describe type and other page formatting information .
simplified: Early minicomputer-based typesetting software was introduced in the 1970s and early 1980s , such as Datalogics Pager , Penta , Miles 33 , Xyvision , troff from Bell Labs , and IBM 's SCRIPT product with CRT terminals . Those replaced the electro-mechanical devices and used text markup languages to describe type and other page-formatting information .