speech output under Unix

[James R. Van Zandt]

A visually handicapped friend is considering the purchase of a '386
machine to run Xenix.  He would like to use a speech synthesizer (i.e. 
ASCII data stream to spoken words) as a console output device. 
Software would also be needed so that he could, for example, ask that
text displayed on a particular part of the screen be verbalized.  I
wrote some software for these functions for use under MS-DOS.  I assume
that the requirements for Unix would be similar - a new or extensively
revised console device driver.  Has anyone else worked on this problem?
Is such software available, either commercially or otherwise?  Does
anyone have another sort of special-purpose console driver I could use
as a starting point?  (I've been programming in C for some time, and use
Unix, but know very little about Unix device drivers.)
 
Please reply by mail, as I do not monitor these newsgroups.
 
                - Jim Van Zandt (jrv at mitre-bedford.arpa)