Hand-held Calculators

Home > Hand-held Calculators

Otis King Type L

The Otis King calculator was sold into the 1970s and was advertised in competition with the early electronic hand-held calculators, so is included as a comparison with the electronic calculators with which it competed.

Otis King Model L

Otis King calculator extended.

Otis King Model L.

Distinctive features: Cylindrical slide rule.

Technical details:
Although described as a calculator (see top photograph) this is really a cylindrical slide rule. By forming it as a cylinder the effective length of the slide rule scale is 66 inches long.

153 mm closed, 262 mm extended, x 31 mm diameter
(6" closed, 10.3" extended, x 1.25" diameter).

"British made throughout".

Carbic Limited,
171, Seymour Place,

There were two versions of this calculator - the Model K and the Model L which had an additional scale for determining logarihms.

An advertisement for the model L in February 1971 gives a price of 85s (4-25p [about $10-50]), which was a fraction of the cost of an electronic calculator (see Bowmar 901B/Commodore C110 at 79 [approx. $195]).
One of the last advertisements for an Otis King calculator (actually the model K) in August 1973 gives a price of 4-65p [about $11-50], which was now comparable to the cost of the cheapest electronic calculator.

The story of Otis King calculators is told in "Otis King Calculators: A History of Production, 1919-1977", by and published by Colin Barnes, ISBN 0 9535039 0 9 - see the United Kingdom Slide Rule Circle's site at http://www.sliderules.org.uk/publications/publications03.htm.

Otis King Model L
Otis King Model L

Otis King calculator closed

Otis King Model L

Otis King calculator extended

Otis King calculator, closed in its box.

The Otis King calculators were popular for many years and continued to sell into the era of electronic calculators due to their very low cost.

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   2000-2015 except where noted otherwise.