Alpha VS 100 - How does it work?

4. How
does
it work?
We
will
talk
about
"phonemes"
, but
don't
worry,
as
you
will
see
later,
you
don't
have
to know
anything
about
them
to be
able
to
use the full
power
of
your
VS-100.
First,
let's
see
how the VS-100
works.
The
hardware
•The
heart
of
the
hardware
is the now
famou3
Votrax
SC-C1
Phoneme
Synthesizer.
A
phoneme
is
one
of the
basic
sounds
needed to
create
spoken
English.
Speech
is
synthesj
zed by
combining
the
sixty
four
different
phonemes
in the
appropriate
sequence.
—
Each of
the sixty
four
phonemes
has
a
standard
Votrax
shorthand
notation.
For example
Al
is the
code
for
the
sound
"A"
in MADE.
In addition
to
the
shorthand
notation,
edch
phoneme
has a
code
used by
the
computer
(a
number
from
to
63). There
is
a complete
phoneme
table
later
in
this
manua
1 .
—
The
computer
sends
the
phoneme
codes
to the
VS-100
using
one c>f
the
256
ports
available.
The VS-100
software
uses
port
11,
but
the
hardware
will also
respond
to
some
other port
numbers.
•When
the VS-100
receives
the
phoneme
code,
it
creates
the
proper
audio
waveform
to
reproduce
the
sound
corresponding
to
the
phoneme.
All
the
waveforms
for
the
sixty
four
phonemes
are
permanently
stored
in the
Votrax
chip.
The
synthesizer
output
is
then
amplified
and
sent
to
the speaker
.
—
The computer
communicates
with
the
VS-100
through
the
8
bit data bus.
The lower
six
bits
<bits
0-5)
are
used to
select
the
phonemes.
The
higher two
bits
(bits 6
& 7)
control
the
pitch
level
.
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