Hand-held Calculators

Home > Hand-held Calculators

TSI Speech+ & other speaking calculators

Speech +

Speech+ speaking calculator with instructions on cassette. The knob at top right is pulled to turn the calculator on and then acts as a volume control. Pressing the button with the loudspeaker symbol (below the "=" button) makes the calculator speak the number on the display. The switch below this button can be used to switch off the speech system.

Telesensory Systems Inc. Speech+

Distinctive features: The first speaking electronic calculator.

Technical details:
Display is 8 digits, red LED. Also speaks the keys pressed and the result.

4-function, %, memory, square root.

Calculator integrated circuit: Texas Instruments TMC1007NL (here date coded mid-1976), based on the TMS1000 4-bit micro-controller. "TSI has custom-programmed a microcomputer in the SPEECH PLUS calculator and is a pioneer in the use of this device. This microcomputer contains the calculating capability. It was used instead of more-conventional, commercially available parts so that we could dictate the way the calculator works and design the keyboard. ..."

Speech processing integrated circuits Telesensory Systems Inc S14001A, General Instruments S14007 (here both date coded early 1977). "The speech circuit for the 24 word vocabulary involves patent pending technology. The speaker is the only moving part and there are two large scale integrated circuits. One is a custom, special purpose microprocessor TSI developed to replace 50 separate integrated circuit packages. The other is a TSI-programmed Read Only Memory (ROM) which has a copyrighted output."

4.8v (4x AA rechargeable).

180 x 115 x 35 mm. (7.1" x 4.5" x 1.4").


Made in USA by Telesensory Systems Inc., Palo Alto, California.

Designed for use by the blind. The top photograph shows the instructions on cassette tape.

Front cover removed

With front cover removed, showing the Texas Instruments micro-controller, used as a calculator chip, and the LED display assembly above the keyboard.

Speech board

The lower, speech circuit board, with the TSI S14001A speech integrated circuit above and the GI S14007 mask ROM chip with the speech data below, the speaker, & the rechargeable cells.

This was the first speaking calculator and a very early use of speech synthesis in a consumer product.

The TSI S14001A was developed by TeleSensory, Inc. in 1975 as a single-IC speech chip for the Speech+ portable talking calculator for the blind. The speech technology was licensed from Forrest S. Mozer, a professor of atomic physics (speech was a spare time thing for him) at University of California, Berkeley[1].

Child's Teaching Speaking Calculator

Child’s Teaching Speaking Calculator

Child's Teaching calculator

Distinctive features: Speaking electronic calculator.

Technical details:Display is 6 digits, red LED, and speaks.

4-functions and maths test mode.

Integrated circuits - Texas Instruments TMS 1000NLL 4-bit micro-controller (here date coded to early 1978) and SN99857. The micro-controller here is another version of the device used in the Speech+ above.

185 x 150 x 29 mm / 7.25 x 5.9 x 1.1".

Manufacturer unknown, made in Hong Kong.
If you know of the manufacturer/distributor please contact us.


With the rear cover removed. The single small circuit board carries the two integrated circuits and the few other components..


  1. Gevaryahu,Jonathan, "TSI S14001A Speech Synthesizer LSI Integrated Circuit Guide", http://si.fileburst.com/s14001a_reveng.pdf.
1) Mechanical Calculators
2) Desk Electronic Calculators
3) Hand-held Calculators
4) Non-Decimal Calculators
5) The Pocket Calculator Race
6) Calculator Companies
7) Calculator Photo Library
8) Calculator Articles
9) British Calculator Companies
10) Puzzle Corner
11) Calculator Time-line
12) Calculator Technology
13) Index to the Calculators
14) Calculator Resources
15) Frequently Asked Questions
16) Update Information
17) Vintage Calculator News
18) Bletchley Park
19) About this site
20) Search this Site

Hand-held Calculators

TI Cal-Tech
Canon Pocketronic
Sanyo ICC-0081 & ICC-82D
Sharp QT-8B
Busicom LE-120A & LE-120S
Sharp EL-8 & Facit 1111
Minolta Minolcom
Brother PRO-CAL 408
Walther ETR3
Bowmar 901B
Ragen Microelectronic
Compucorp 324G
Sharp EL-811 & derivatives
Royal Digital III & IV
Busicom LE-100A handy
Busicom LE-80A handy
Hewlett Packard HP-35
Canon LE-10
Rapidman 800
Texas Instruments 2500
Lloyd's Accumatic 100
Sinclair Executive
Casio Mini
Sanyo ICC-809
Sharp EL-801
Texas Instruments SR-10
Sperry Remington 661D & 661
Olympia CD 81
apf Mark V
Ramsgate M-11
Olivetti Divisumma 18
Iain Jones International Mini A
Hewlett-Packard HP80
Litronix Checkmate
Heathkit IC-2009
MITS 150
Summit Ko9V, K16 & SE88M
Unicom 102
Victor 85 "Tallymate"
Elka 101
RFT minirex 75
Sharp EL-120
Sharp EL-805
Bowmar MX-55
Atlas-Rand, Berkey, & Keystone
Hewlett-Packard HP-65
Casio fx-10
Casio AL-8 & family models
Commodore 776M & 796M
Novus 650 "Mathbox"
Rockwell 8R
General Instrument EZ3000
Check, billfold, wallet calculators
Monte Carlo
Texas Instruments Spirit of '76
Pulsar Calculator Watch
Compuchron Calculator Watch
Adler Lady & Sir
Elektronika B3-18A & C3-15
Commodore S61
"Standard Type 1"
Sharp EL-8026
Texas Instruments TI-30
Canon Multi 8
Casio ST1
Wrist Calculators
Kosmos I & Kosmos Astro
Hanimex Calculator-Recorder
Navigation Calculators
TI58 Special Function Calculators
Sandvik 842S Coromant
"Standard Type 2"
Panasonic Electronic Ruler
Teal Photon
Casio Mini Card LC-78
Feet & inches calculators
SCAT Specialist Calculators
Sharp EL-826
Sharp EL-825
Sanyo CX-1
Elektronika MK-33 etc
Sharp PC1211/Tandy TRS80 PC1
Slide Rule
Otis King L

Vintage Calculators

© Text & photographs copyright Nigel Tout   2000-2014 except where noted otherwise.