A few days ago there was some discussion of speech and sound chips, which
prompted me to dig in the spares box and extract a TMS5220 speech processor
and the ROM that goes with it, made by Texas Instruments.
For those who don't know, this was a rather interesting speech processor:
it worked by setting up digital filters to model certain characteristics of
the human vocal tract, and then used those filters (dynamically adjusted)
to turn white noise (simulating moving air) or other sounds into speech.
The ROM didn't store digitised sound at all, instead it stored the
information about what type of source to use and what filter parameters to
set up. Hence it was not much use for anything except speech, but it did a
pretty good job of that and used less memory than, say, a Digitalker did (I
have a Digitalker chip set as well).
The TMS5220 was most often used with special serial ROMs, and was used as
the (optional) speech processor in the BBC Microcomputer -- that's why I
have a couple of sets. It was also used in some arcade machines, in one if
the Texas home micros (TI99/8?), one of the Coleco machines (I think), and
an obscure British 68000-based machine called a uMicro 2000.
Texas made a couple of standard vocabulary Phrase ROMs, and custom ones for
particular pusposes. The arcade machines and BBC Micro used custom PHROMs,
-- TMS6100NLL in the Beeb -- but one I have out of a uMicro 2000 has a
generic part number: VM61002NL. I know that the first standard vocabulary
ROM was type VM61001NL so I imagine what I have is another standard part.
Alas, I can no longer find the data sheets for either the TMS5220 or the
PHROMs, and a web search hasn't turned up anything useful. Texas' website
no longer has any info on those devices, neither does the company who deal
with their obsolete products. Does anyone have any information about these
things? I'd like to see (or hear!) what's in the PHROM I've found.
--
Pete Peter Turnbull
Network Manager
University of York
Received on Sun Jun 17 2001 - 17:31:36 BST