DID TEURS

repository.mdp.ac.id
  • No tags were found...

MagaZine - Free and Open Source Software

Photo B. The S2A speech synthesizer board from Te/esensory

Systems, Inc. The large Ie is the CRC micro-cccuotler.

The entire 24-word vocabulary is contained in the smaller

16K ROM. All connections are by way of the double-sided

card edge connector (10 pins per side).

work. But, recogn izing potential

need for a specific

multiplex rate, the designe

rs at lSI allowed provision

for user control of the multiplex

rate on the l SI 7031

counter Ie. By removing

t he capacitor normally

u sed for t he o n-board

clock, it is possible to control

the sca n oscillator in

the chip.

A Scan Reset pin is provided,

which advances the

sca n counter in the IC to the

left-ha nd digit- Th is pin

could be used to reset the

scan counter, but it wasn't

found to be necessary.

However, by applying a

pulse to pin 39, the scan inpu

t, the counter IC would

step across t he display, left

to right, just as was desi red!

The actual interface is

very simple, consisting of

just one 4D-cent CMOS gate

package in addition to power

supply and a udio amplifier

parts (see Fig. 1). The

speech readout is initiated

by pressing the Speak

switch, which sets an R-$

flip-flop a nd allows the

st robe line to go true. There

will be a short pulse when

the Busy line signals the

end of the word, and this

acts as a c lock pulse to

move the scan counte r in

the counter Ie on to the

next digit.

The process continues

until the last digit is spoke n.

when the pos itive edge

from the eighth counte r

digit serves to reset the flipflop

a nd term ina te the

speech. The only connections

required to the counter

a re the four BC D data

lines, the addition of a

switch to the scan input to

se lect visual or audible drsplay.

and a wire to the

eighth digit strobe. Because

of the ease of interfacing

this circuit, it should be

eas ily d u p licate d, a nd

TSI Model S2A Synthesizer

Vocabulary list

Data Code Word

(Octal)

000

001

002

003

004

005

006

007

01 0

011

012

013

0 14

0'5

01.

017

020

021

022

023

02'

025

02.

027

030

Oh

One

Two

Three

Four

Five

Six

Seven

Eight

Nine

Itmes.Mtnus

Equa ls

Percent

Not used

Low

Over

Root

Em

Times

Point

Overflow

Minus

Plus

Clear

Swap

Photo C. Inside the counter. The speech board is visible on the feft and the power supply

andamplifier-interface circuit board are on the right. Note D IP-plug connections to counter

mainframe. Large modufe at right is dddc converter that generates -10 vo lts fo r synthesizer.

Speaker is mounted to top cover.

Table 1. The " voice" o f the

S2A is that of Dr. Forres t

Mozer, inventor of the

speech-generation afgorithm

used by the LSI controlfer.

The speech synthesizer

is a static-sensitive device

and normal MaS handling

precautions should be

observed.

54 73 Magazine· April, 1981

More magazines by this user
Similar magazines