> "BI" fonts can, it seems, largely be traced to the impact 

> of PostScript

There was no room for BI on the C/A/T. It appeared in

troff upon the taming of the Linotron 202, just after v7

and five years before PostScript. 

> Seventh Edition Unix shipped a tc(1) command to help

> you preview your troff output with that device before you

> spent precious departmental money sending it to the

>  actual typesetter.

Slight exaggeration. It wasn't money, It was time and messing

with film cartridges, chemicals, and wet prints. You could buy a

lot of typesetter film and developer for the price of a 4014. 

Doug