> On Mar 23, 2020, at 14:59, arnold@skeeve.com wrote:
> 
> Clem Cole <clemc@ccc.com> wrote:
> 
>> To answer Ed's question, it came out of Research, but first as part of the
>> typesetter support - *i.e.* 'Typesetter C', which was on V6 and PWB
>> 1.0 [the new troff replacement was being written by Brian] .
> 
> The troff replacement was somewhat after V7.  The troff that shipped with V7
> was still only for the CAT.

Yes, "Typesetter C" was to accommodate the C Version of troff written
by Ossana and I checked the source, it doesn't use stdio.

	jaap