[TUHS] speak and speech synthesis

[Will Senn via TUHS]

In a similar investigation to my graphics dive, this time into speech 
synthesis, I found that |/dev/vs| talks to the synthesizer through a 
DC-11. I’m trying to determine the interrupt/vector assignment for that 
device—specifically the Federal Screw Works Votrax interface.

There is quite a bit of useful material scattered across UNIX V4 through 
V6. From that, I can reconstruct the system generically: add the |vs| 
driver to the kernel, create |/dev/vs|, add PCM audio support to SIMH, 
and translate the historical phoneme stream into approximate speech 
based on what can be pieced together from the source and documentation. 
This "should" work and get speak working...

I’d prefer, though, to reproduce the original interface somewhat more 
faithfully. The V4/V6 |vs.c| sources give the CSR address (|0174150|) 
and the receive/transmit interrupt routines (|vsrintr| and |vsxintr|), 
but I haven’t yet found the actual interrupt vector assignment used for 
the Votrax/DC-11 installation.

If anyone has an old kernel configuration, |mkconf| entry, low-core 
|l.s|, hardware note, or other documentation showing how the Screw Works 
Votrax interface was actually vectored, I’d be very interested in seeing it.

Also, Doug, you wrote technical report 14, which seems canonical about 
how speak worked. Is that the best source you or anyone else knows of 
vis a vis v6's implementation?

Thanks,

Will