High-quality printed reproductions have been made from a number of vintage calculator instruction manuals. The original documents have been scanned at high resolution and extensively edited to remove blemishes, improve legibilty, and correct the contrast of photographs. Most are printed in black-and-white only; some have colour covers; some have spot colour in the text and diagrams; some have full-colour illustrations (as indicated below). All of the manuals are written in English unless otherwise noted. It is hoped that these manuals will broaden the understanding and appreciation of these vintage machines, and so contribute to their preservation. Printed copies can be made available to machine owners for a nominal fee to cover costs and postage.

The manuals are described and illustrated below in alphabetical order. Please use the Enquiry Form for further information on any of these items.

**
Addometer - Directions (c.1930)**

Single page, A4 size. (Original 8-1/2" x 11").

This is a single sheet of Directions for using the Addometer. The
instructions cover using the stylus, clearing the machine, and
performing addition, subtraction, and multiplication.

**Instructions for operating the
Burroughs Calculator (1925)**

32 pages plus covers, A4 size, comb bound.

31 illustrations, 5 pages of tables.

This is a very detailed and well-illustrated operating manual for
the Burroughs key-driven calculator. The illustrations are of the
1925 model, but the instructions are applicable to any key-driven
"Class 5" machine, including the later electric models. The
manual covers fingering techniques, basic addition and subtraction,
detailed procedures for multiplication and division, and examples of
many types of business calculations. You should be able to pass the
Comptometer Operators'
Certificate Test after completing the course of instruction in
this manual.

**Instructions for Use -
Brunsviga Model 13Z (1950s)**

20 pages plus colour covers, foldout, A5 size (landscape), comb bound.

This manual gives a very clear explanation of the operation of
the Brunsviga 13Z pinwheel calculator. It describes the four basic
operations (addition, subtraction, multiplication, and division,
or ASMD for short), including short-cut multiplication and three
methods for division. Examples of more complex calculations include
percentages, interest, square roots, and non-decimal units. There
are 4 pages of tables for conversion of English weights and currency,
interest factors, and grosses. (1 gross = 1 dozen dozen, or 144
items).

**Instructions for Use -
Brunsviga Model 13RK (1960s)**

36 pages plus colour covers, foldout, A5 size (landscape), comb bound.

This manual is a very clear and detailed description of the
operation of the Brunsviga 13RK machine, which includes the
back-transfer and coupled clearing mechanisms. The manual is written
in the form of a personal tutorial which takes the new user step by
step through all of the basic operations and the procedures for
typical calculations. It begins with how to turn the handle, and
ends with non-decimal calculations, pro-rata, interest, and square
roots. There are 9 pages of tables and conversion factors.

**Methods of Operating the
Comptometer (1894-1928)**

72 pages plus covers, 5-1/2" x 8", stapled booklet.

The instruction manual for the Felt & Tarrant "Comptometer" was
first produced in the 1880s, and was progressively updated to cover
the new features of subsequent models. This very comprehensive edition
was produced in 1928 for the Model J Comptometer, but still contains
sections of text from 1894 and illustrations from 1909. Although the
Comptometer mechanism changed gradually over the years, the methods
of operating were basically the same from the first Comptometer to
the last. This manual can be used with any model with only minor
adjustments.

The manual focusses on methods of operating the machine in the most efficient manner, with many half-page illustrations showing hand positions and operating techniques. There are detailed procedures for calculations from simple addition to compound interest and square roots, and for the correction of errors via the "Controlled-key" mechanism. There is a section on maintenance and lubrication, and an appendix on the theory behind the use of complements in subtraction and division.

**Easy Instructions for operating the Controlled-Key
Comptometer (c.1940)**

20 pages plus colour covers, 6-1/2" x 8", stapled booklet.

This little manual gives basic instructions and practice examples
for calculating on the Comptometer (any model). The book begins with
basic 2-finger exercises, then proceeds through various techniques
for addition, multiplication, subtraction, and division. It gives
particular attention to the setting of decimal points and the
proving of results. There are two pages of reciprocal tables for
use in division.

**Rule for extracting Cube Root with the
Comptometer (1911)**

12 pages plus covers, 5-1/4" x 7", stapled booklet.

This little booklet from Felt & Tarrant has two pages of
instructions and ten pages of tables to enable the extraction of
cube roots on the Comptometer. The booklet is interesting in that
it refers to the "Controlled-key" Comptometer, but the copyright
notice is dated November 1911. Other Felt & Tarrant publications
state that the first Controlled-key machine was the Model E, which
was not introduced until March 1913.

**
Comptometer Model C - Repair Instructions (1909)**

14 pages plus covers, 2 fold-out drawings, 7" x 7-3/4", comb bound.

The first section of this manual gives a detailed tour of the
internal mechanism of the Model C Comptometer. The second section
illustrates all of the major parts and assemblies, and describes how to
remove and replace individual parts in a malfunctioning machine. The
final section lists the contents of the technician's tool kit and
the spare parts kit. There are three detailed line drawings of the
mechanism, and three small photographs. The manual is also applicable
to the adding and clearing mechanisms of the more common Model F
Comptometer. (The cover is missing from my original manual, but a
facsimile has been re-created in the style of the other Comptometer
repair manuals).

**Repair Instructions for
Model J Comptometer (1926)**

44 pages, 8-1/2 x 5-1/2" (landscape), comb bound.

This technical manual gives a detailed description of the changes
made between the Model H and the Model J Comptometers, especially in
regard to the carry mechanism and the various springs. It includes a
listing of all the new parts and assemblies for the decimal,
fractional, and Sterling currency machines, and details of the
many combinations of gears and springs for each application.
The typewritten booklet has been reproduced via OCR with the
original formatting.

**Instructions for Servicing -
Electric Model K Comptometer (1934)**

8 pages, 8-1/2" x 5-1/2", stapled booklet.

This brief technical manual for the electric Model K machines was
issued to the Comptometer oilers who carried out the regular monthly
servicing at the customers' premises. The manual sets out detailed
procedures for intial inspection, full and partial lubrication, and
final checks before and after reassembly. There are some general
notes on lubrication, and a warning to the oilers not to exceed
their authority by attempting more complex repairs. The typewritten
booklet has been reproduced via OCR with the original formatting.

**How to use the
Compucorp Micro Scientist Model 320/322 (1973)**

28 pages plus covers, 7" x 5", stapled booklet.

This is the basic instruction manual for the Compucorp "Micro
Scientist" series of portable electronic scientific calculators from
the early 1970s. Although labelled for the Model 320 (basic) and 322
(programmable) machines, it can also be used with the 324 (dual program)
and G-suffix (Grad) models. The calculating functions are the same
for all of these models. The manual is written in an informal style,
but covers all of the details including register arithmetic and
scratchpad programming.

**Instructions for use -
Contex 10 (1965)**

24 pages plus covers, spot colour, 7" x 5" (landscape), stapled booklet.

This little manual provides much more detail about the operation of
the Contex 10 than is found on the brief instruction label under the
machine. Contents include basic operations, semi-automatic division,
decimal points, continuous and short-cut multiplication, left-to-right
multiplication, percentage calculations, and subtraction below zero.

**Instructions for use -
Contex 20 (1963)**

24 pages plus covers, spot colour, 7" x 5" (landscape), stapled booklet.

This manual describes the operation of the motor-driven Contex 20
calculator. The contents are otherwise similar to those of the
Contex 10 manual above.

**Instructions for use -
Contex 30 (1967)**

24 pages plus covers, spot colour, 7" x 5" (landscape), stapled booklet.

This manual describes the operation of the motor-driven Contex 30
calculator with the fully-automatic digit-by-digit multiplication
mechanism. The contents are otherwise similar to those of the
Contex 10 and 20 manuals above.

**Manual of the Facit Calculating Machine
Model TK (1948)**

44 pages plus covers and foldout, 130x195mm, stapled booklet.

This 1940s booklet is the Operator's Manual for the early Facit TK
pinwheel calculator, but it can also be used with the later models
NTK and C1-13. The booklet describes the controls and operation
of the machine and the basic calculating procedures, with examples of
typical business calculations. There is a 4-page mathematical chapter
on calculating square roots to various degrees of precision, and
8 pages of tables.

**How to become an expert calculator on the
Facit NTK (1954)**

24 pages plus covers, colour, A5 size, stapled booklet.

This 1954 booklet is a basic Operator's Manual for the hand-cranked
Facit NTK pinwheel calculator. The first half of the booklet explains
the controls and the recommended methods for operating the machine.
The second half explains the basic calculating procedures. Examples
include ASMD, long and negative numbers, short-cut and continuous
multiplication, and division by use of reciprocals. The booklet is
well illustrated, and has numerous "Facit Man" cartoons.

**
Facit C1-13 Pinwheel Calculator - Handbook (1965)**

28 pages plus covers and fold-out, colour, A5 size, stapled booklet.

This manual describes the controls and operation of the Facit
C1-13, with examples of many types of business calculations and
3 pages of conversion tables. The illustrations are of the mid-1960s
model, but the manual can be used with any Facit TK, NTK, or C1-13
machine from the 1930s to the 1970s.

**
Facit CM2-16 Pinwheel Calculator - Handbook (1962)**

32 pages plus covers and fold-out, colour, A5 size, stapled booklet.

This manual describes the controls and operations of the CM2-16
hand-cranked machine with the 10-key numeric keypad. It gives
particular attention to the use of the back-transfer mechanism from
both the accumulator and the counter registers. There are worked
examples of many types of business calculations, and 8 pages of
conversion tables.

**How to become an expert computor on
Facit NEA (1954)**

24 pages plus covers, colour, A5 size, stapled booklet.

This booklet is a basic instruction manual for the Facit
semi-automatic pinwheel calculator Model NEA. The manual describes
all of the controls and operations, and gives examples of basic
calculations.

**How to calculate on the
Facit NE (1953)**

8 pages, A5 size, stapled booklet.

The Model NE is a cheaper version of the Model NEA (above) without
any of the automatic features. This instruction booklet for the
Model NE is provided as a supplement to the manual for the Model NEA.
The booklet describes the differences between the two machines, and
gives revised operating instructions where necessary.

**How to become an expert computor on
Facit ESA-0 (1951)**

24 pages plus covers and supplement, colour, A5 size, stapled booklet.

This booklet is a basic instruction manual for the Facit
fully-automatic calculator Model ESA-0. The "0" indicates
power-assisted clearing keys, but the machine is otherwise similar to
the earlier "Electric Super-Automat" Model ESA. The manual describes
all of the controls and operations, and gives examples of basic
calculations. The 1-page Supplement explains the functions of the
secondary control lever.

**
Facit CA1-13 Pinwheel Calculator - Instruction Book (1964)**

36 pages plus covers and fold-out, colour, A5 size, stapled booklet.

This manual explains all the controls and operations of the
fully-automatic Model CA1-13, with examples of many types of business
calculations and 6 pages of conversion tables.

**More ways to get the most out of your
Facit (1952)**

48 pages plus covers, colour, A5 size, stapled booklet.

This manual provides a broader and more complex range of examples
than were included in the basic operator's manuals for the 1950s
machines. It describes a range of common business and commercial
calculations and shows how they can be done most efficiently on the
Facit calculator. Examples include constant factors, simultaneous
multiplication and division, pricing and mark-ups, chain discounts,
payrolls and deductions, interpolation, interest, English currency,
and calculating with very large numbers. There are separate
explanations (where appropriate) for the manual, semi-automatic,
and fully-automatic machines (TK, NEA, and ESA-0 respectively).
The same methods can also be used with the similar 1950s models NTK,
NE, and ESA. The book has numerous cartoon illustrations, and 9 pages
of conversion tables.

**Short-cut calculations with
Facit (1958)**

48 pages plus covers, colour, A5 size, stapled booklet.

This book is a later version of the "More ways to get the most..."
manual (above). The examples, illustrations, and conversion tables
are mostly the same, but the explanations have been updated where
necessary to suit the newer C1-13, CS1-13, and CA1-13 machines.

**Friden Automatic Calculators - Operating Instructions -
General Utility Model "D"
(1940-49)**

16 pages including covers, 9" x 4", stapled booklet.

This small but quite comprehensive manual describes the operation of
the Friden "General Utility" calculator Model D. This is a semi-automatic
machine with manual add-and-shift multiplication and fully automatic
division. The manual describes the operation and use of the controls
(including the double division key), and gives step-by-step examples of
many types of business calculations.

**Friden Fully Automatic Calculator
Model ST - Operating Instructions - (1940-50)**

22 pages including covers, 9" x 4", stapled booklet.

This manual describes the operation of the Friden "Super-matic
Tabulating" calculator Model ST, which was the predecessor of the
re-styled Model STW. This is a fully-automatic machine with a second
10-key multiplier keyboard. The manual describes the operation and use
of the controls (including automatic tabulation and the double division
key), and gives step-by-step examples of many types of business
calculations.

**
Friden Automatic Calculators Models CW and DW
- Operating Instructions and Suggestions (c.1950)**

16 pages plus covers, A5 size (original 8-1/2 x 5-1/2"), stapled booklet.

This manual describes the controls and operation of the Friden
semi-automatic calculators Models CW and DW with automatic division
and manual add-bar multiplication. There are step-by-step examples of
many types of business calculations. The instructions can also be
used with the earlier Friden Models
C and D "with very few
exceptions - which are easily recognised".

**
Friden Fully Automatic Calculator Model STW
- Operating Instructions and Suggestions (1958)**

80 pages plus covers, A5 size (original 8-1/2 x 5-1/2"), comb bound.

This is a very comprehensive (80-page) manual for the
fully-automatic Friden Model STW calculator with the 10-key multiplier
keypad. The manual describes and illustrates all of the controls and
features of the machine, and explains how they are used in typical
business calculations. More complex examples include date calculations,
interest and amortization, invoicing, and half-cent adjustments. Shorter
instructions can be found in the 1963 STW manual (below), or in the manual
for the earlier Model ST (above).

**
Friden Model SBT Calculator - Operating Instructions (1959)**

16 pages plus covers, A4 size (original 8-1/2 x 11"), comb bound.

This concise but well-illustrated manual describes the
fully-automatic Friden Model SBT calculator with the the 10-key
multiplier keypad and the back-transfer mechanism. There are worked
examples from many types of business calculations. The manual itself
is interesting in that it was typeset on an early
tape-controlled word processor (Friden's own "Justowriter"), and
uses computer terminology (such as "programs") to describe the
setting-up of the machine for particular calculations.

**
Friden Fully Automatic Calculator Model STW - Instruction
Manual (1963)**

24 pages plus colour covers,
A4 size (original 8-1/2 x 11"), comb bound.

This 1963 version of the STW instruction manual gives a concise
introduction to the machine through a series of worked examples. Each
example includes a "program" of machine settings, a highlighted
keyboard diagram, and a step-by-step operating procedure. Topics
include grand totals, discounts, pro-rata, and the "Fives method" for
square roots. The manual includes a fraction-to-decimal table and a
page showing other Friden models, including the EC-130
electronic calculator.

**
Lagomarsino Totalia S4-GT - Operating Instructions (1969)**

6 pages, A5 size, loose leaf (in German).

This little manual gives concise operating instructions for the
Totalia S4-GT fully-automatic printing calculator. It describes the
procedures for multiplication and division, constant storage,
grand total, back-transfer, and percentage calculations, with
brief examples.

**
MADAS product catalogue (1961)**

8 pages including covers, A5 size, stapled booklet.

This catalogue gives illustrations and brief descriptions of the
nine basic machines in the MADAS product range for 1961, from
hand-cranked to fully-automatic. It mentions the variants of each
model, and includes a list of optional features that were available
on special order. The catalogue has been re-formatted from a long
single sheet into an 8-page booklet.

**Directions for Operating the
MADAS Models 16LS, 20LS, and 20LZS (1952)**

8 pages including covers, A5 size, stapled booklet.

This manual covers the semi-automatic MADAS machines, Models 16LS,
20LS, and 20LZS. There is a 2-page illustration, a full description
of all of the controls, and some basic instructions for addition,
subtraction, manual multiplication, and automatic division. The manual
has been re-formatted from a long single sheet into an 8-page booklet.

**Directions for the Proper Use of the
MADAS Fullautomatic Models 20AV and 20AZV (1942)**

8 pages including covers, A5 size, stapled booklet.

This manual is similar to the one above, but covers the
early fully-automatic Models 20AV and 20AZV. There is an illustrated
description of all of the controls, and brief instructions for
addition, subtraction, automatic multiplication and division, and
back-transfer. The manual has been re-formatted from a long single
sheet into an 8-page booklet.

**Directions for the Proper Use of the
MADAS Triplex 20 BTG and 20 BTZG **

20 pages including covers and fold-out, A5 size, stapled booklet.

This is a much more comprehensive manual for the late-model
fully-automatic machines with the "Triplex" carriage (Models 20 BTG
and 20 BTZG). The manual illustrates and describes all of the controls
and functions of the machines. It includes detailed instructions for
addition, subtraction, multiplication, and division, including
back-transfer operations, decimal setting, handling of complements,
and the use of the auxilliary "Triplex" register. The instructions
are also applicable to the earlier Model ATG (except for the location
of the negative multiplication control).

**How to use your
MADAS calculating machine**

32 pages plus covers and illustrations, A4 size
(originally 10"x8"), comb bound.

This is a third-party manual written by Richard Goodman MA, BSc,
from the Brighton College of Technology. It was printed in loose-leaf
format and assembled in sections by the dealer to suit the type of
machine purchased. There is a common introduction (3 pages), then one
of three alternative sections to describe the manual, semi-automatic,
or fully-automatic machines (13 pages plus illustrations), followed by
a common section giving examples of quite complex commercial,
mathematical, and statistical calculations (16 pages).

**Operating Instructions for
Marchant "Silent Speed" Calculators (1943)**

40 pages plus covers, colour, A4 size (originally 6" x 9"), comb bound.

This manual covers all of the Marchant "Silent Speed" calculators
to 1943. It applies to both the semi-automatic D-series models with
the bar-type multiplier, and to the fully-automatic M-series machines
with the single-row multiplier keyboard. The manual describes the
controls and features of the machines, and explains how they are used
in basic and commercial calculations. Emphasis is given to the correct
use of carriage tabulation, the setting of decimals, and the proving
of results. The manual contains many useful hints for efficient
operation, and gives details of several key combinations which are not
immediately obvious from the keyboard. The instructions and examples
can also be used with the later Figuremaster and Figurematic machines,
with only minor adjustments. This reproduction manual is printed at
the original size (6" x 9") on A4 paper.

**Simple Instructions for
Marchant Figurematic Calculator Model ADX (1953)**

8 pages including covers, A5 size, stapled booklet.

This manual describes the operation of the Marchant
fully-automatic calculator Model ADX. The manual describes all of the
controls and features of the machine, and includes sections on
automatic multiplication and division, setting of decimal points,
and use of the carriage tabulator. This manual has been reduced
by 8% from the 9"x6" original so that it can be printed on A4 paper.

**Operating Instructions for
Marchant Semi-Automatic Calculator Model DCR (1960)**

8 pages including covers, A5 size, stapled booklet.

This manual describes the operation of the Marchant semi-automatic
(or D-series) calculator Model DCR from around 1960. The
semi-automatic machines are essentially the same as the
fully-automatic, except that they do not have the automatic multiplier.
The manual includes sections on short-cut multiplication, using the
carriage tabulator, and automatic division setup. This manual has
been reduced by 8% from the 9"x6" original so that it can be printed
on A4 paper.

**Operating Instructions for
Marchant "Deci-Magic" Model SK (1962)**

32 pages plus covers, A4 size (originally 8.5" x 11"), comb bound.

This manual describes the operation of the Marchant "Deci-Magic"
calculator with the front multiplier register, also known as the
"single-keyboard automatic" or SKA. This 1962 edition shows the SCM
Model SK in the tan-coloured casing, but it can also be used (with
only minor adjustments) for the earlier Model SKA in the streamlined
blue casing. The manual describes all of the keyboard controls,
the basic operations, and techniques for automatic multiplication
and division (including accumulations in the counter register).
Worked examples include chain discounts, pro-rating, statistics,
and square roots.

**
Millionaire Calculating Machine - operating instructions (c.1900)**

24 pages plus covers, A5 size, stapled booklet.

This manual describes and illustrates the controls on the
Millionaire calculating machines, and describes the procedures for
addition, subtraction, multiplication, and division. Example
calculations include proportions, interest, and square roots.

**How to Operate
Monroe Adding Calculator Model MA-7 (c.1940)**

Single sheet, spot colour, 8-1/2" x 11", folded pocket card.

This little manual for the Monroe MA-7 semi-automatic calculator
is in the form of a single letter-sized sheet folded into a 6-panel
pocket reference card. It describes the location and operation of the
controls, the methods for performing basic calculations, and the
setting of decimal points.

**Operating Instructions for
Monroe Models LN-160 and LN-200 (1953)**

20 pages, colour cover, A5 size, stapled booklet.

This manual covers the desktop versions of the hand-cranked
L-series machines, models LN-xxx. There is an illustration and
description of the controls, with instructions and practice problems
for addition, subtraction, multiplication, and division. There are
detailed instructions for setting the decimal points. Although
written for the 1953 models, the manual is equally applicable to
any of the hand-cranked Monroe machines from the 1920s to the 1970s.

**Operating Instructions for
Monroe Models L-160-X and L-200-X (1953)**

20 pages, colour cover, A5 size, stapled booklet.

This manual covers the portable and "Executive" versions of the
hand-cranked L-series machines, models LX-xxx, L-xxx-X, and LN-xxx-X.
There is an illustration and description of the controls, with
instructions and practice problems for addition, subtraction,
multiplication, and division. There are detailed instructions for
setting the decimal points. Although written for the 1953 models,
the manual is equally applicable to any of the hand-cranked Monroe
machines from the 1920s to the 1970s.

**Monroe Compact Electric Calculator Model LA-9 - Instructions (1960)**

20 pages plus foldout, colour cover, 5"x7", stapled booklet.

This manual describes the controls and operation of the
motor-driven "Compact Electric" L-series machines. While written
specifically for the late-model LA-9 with the lever-operated carriage
shift, the instructions can also be used (with minor adjustments) with
any of the earlier LA machines with the rotary shift control. The
manual has instructions and practice problems for addition,
subtraction, normal and short-cut multiplication, automatic division,
and setting of decimal points. Practical examples include invoicing,
pro-rating, and payroll calculations.

**Operating Instructions for
Monroe Automatic Calculator Model CSA (1954)**

14 pages plus covers, A5 size, stapled booklet.

This manual describes the operation of the Monroe CSA-8 and CSA-10
fully-automatic calculators (with 8 and 10 columns respectively). There
is a full description of all the controls (including the un-labelled
buttons), with instructions and examples for addition, subtraction,
multiplication, division, decimal points, and several types of business
calculations. In this 1954 edition (reprinted 1964) Monroe applied the
new computer terminology to mechanical calculating by describing the
machine setup for each problem as a "program".

**Monroe machine methods for
the extraction of square root (1953)**

12 pages plus covers, A5 size, stapled booklet.

This manual describes three mechanical methods for the extraction
of square roots. While written specifically for the Monroe calculator,
the same methods can be used on any similar machine.

**Instructions in Multo
calculation (1959)**

8 pages including covers, A5 size, stapled booklet.

This manual describes the controls and operation of the early Multo
pinwheel calculators (Models 3, 13, 103, and 113). It covers basic
operations (ASMD), back-transfer, short-cut and chain multiplication,
and setting of decimal points. The manual has been re-formatted from a
long single sheet into an 8-page booklet.

**Multo Instructions (1966-70)**

12 pages plus covers, spot colour, A5 size, stapled booklet.

This manual covers the late-model Multo pinwheel calculator. The
original Multo calculators (above) were discontinued in 1966 (when
Addo was absorbed into the Facit/Odhner organisation), and were
replaced with a re-badged Original-Odhner Model 239. The manual is
essentially the same as the Odhner instruction manual "Let
Original-Odhner do the work for you" (below), with minor changes in
terminology and in a larger A5 format. It covers basic operations
(ASMD), back-transfer, short-cut and chain multiplication,
additive and subtractive division, and calculation of square roots.

**Multiply and divide on an
Original-Odhner (c.1950)**

32 pages plus covers, spot colour, 118x210mm, stapled booklet.

This well-illustrated manual from about 1950 describes the
features and operation of the Original-Odhner range of pinwheel
calculators. The illustrations show the new 100-series Models 127 and
129, together with the previous Models 24, 37, and 39. The instructions
cover the proper set-up and operation of the machine, basic arithmetic
(ASMD), and practical calculations. The emphasis is on multiplication
and division, with examples including proportions, discounts,
percentages, and square roots. There are several half-page
illustrations showing the machines in use, an internal view, and
a (politically incorrect) map of Odhner agencies around the world.

**Let Original-Odhner do the
work for you (c.1955)**

20 pages including covers, spot colour, 127x127mm, stapled booklet.

This little manual gives a concise description of the features
and operation of the Original-Odhner pinwheel calculator, with examples
covering basic arithmetic (ASMD), proportions, discounts, percentages,
and square roots. The illustrations show the mid-1950s Model 227, but
the manual is equally applicable to any of the 200-series models (and
in principle to any of the earlier models). The young lady on the
cover is said to be Sweden's Miss World winner from 1952.

**Original-Odhner
Calculator Model 239 - Operating Instructions (c.1955)**

49 pages plus covers, A4 size (originally 10" x 8"), comb bound.

This is a third-party manual prepared by the Educational Division
of Block & Anderson in London. (B&A were a major firm of office
equipment suppliers who handled many types of calculating machines).
The manual was most probably used in their in-house training courses
for operators of the Odhner 239 machines. The manual gives detailed
instructions for basic arithmetic (ASMD), short-cut multiplication,
chain calculations, squares and square roots, setting of decimal
points, and calculating in Sterling currency. Each section has worked
examples and test questions (with answers). The focus is on the
detail of operating the machine rather than on its application to
business calculations.

**Operating Instructions -
Odhner 1048/1049
(Nov. 1970)**

8 pages including colour covers, 210x210mm, comb bound.

This 1970 manual describes the features and operation of the
late-model pinwheel calculators Models 1048 and 1049. Model 1049 is
essentially the same as the Model 239, while the 1048 is the same again
but without the setting check dial. The instructions cover the basic
operations (ASMD), discounts and percentages, short-cut multiplication,
and the setting of decimal points. The manual has been re-formatted
from a long single sheet into an 8-page booklet.

**Practical Calculations (Rex) for the
Original-Odhner
Calculator (c.1950)**

48 pages plus covers, A5 size, stapled booklet.

This book is intended "for the Odhner operator (and especially
the Odhner salesman) who wants to know calculations more advanced
than those of the elementary kind..." It describes several interesting
computational techniques, including the use of complements and
"negative division" in chain calculations. There are worked examples
of about 50 different types of commercial and business calculations.
While the book is written specifically for the Odhner 100-series
machines, the methods described can be used on any similar pinwheel
calculator. (The term "Rex" appears to come from the German word for
calculation, although it does not have this meaning in English).

**Original-Odhner
Table of Decimal Equivalents (c.1950)**

11 pages plus covers, A5 size (landscape), comb bound.

Books or charts of conversion tables were widely used to assist
in calculations in non-decimal systems. This compact booklet contains
ten of the most useful tables of decimal equivalents for common
fractions, English currency, interest rates, English weights (pounds,
quarters, hundredweight, and tons), dozens and gross, hours and
minutes, feet and inches, and timber in board (or super) feet. This
booklet was originally distributed to Original-Odhner customers, but
the tables can be used with any calculating machine.

**Instruction Book -
Odhner XX11C (1965)**

16 pages including covers, spot colour, 127x127mm, stapled booklet.

This 1965 booklet describes the controls and operation of the
Odhner XX11C electric adding machine with the credit balance
and short-cut multiplier mechanisms. Example calculations include
pricing, discounts, and accumulative multiplication.

**
Otis King's Calculator - Operating Instructions**

8 pages including covers, 8" x 5", stapled booklet.

This booklet describes the construction and operation of the
Otis King cylindrical slide rules, Models K and L. Examples include
multiplication and division, proportions, percentages, Sterling
currency, powers and roots, and methods for locating the decimal
point in complex calculations. The manual has been re-formatted
from a long single sheet into an 8-page booklet.

**
PLUS Rapid Adder - Operating Instructions**

12 pages plus covers, A5 size, stapled booklet.

This little manual was prepared for use in the PLUS training
courses in Australia. It covers basic addition and multiplication in
both Sterling and decimal systems, with practice examples and
currency conversion tables.

**
Sanyo ICC-82D - Instruction Manual (1970)**

18 pages plus covers, spot colour, 175x125mm, stapled booklet.

This is the manual for Sanyo's classic ICC-82D portable
battery-powered calculator from 1970. The book gives very detailed
explanations, on the (quite reasonable) assumption that the reader
has never seen an electronic calculator before. In addition to covering
the basic operations, it explains all of the early peculiarities which
are not immediately obvious, including double-precision operation,
chain calculations, and the display of complements for negative
numbers.

**
Sanyo ICC-1123 - Instruction Manual (1973)**

40 pages plus colour covers, 180x130mm, stapled booklet.

This manual describes the features and operation of Sanyo's
ICC-1123 calculator from 1973. It is also suitable for the earlier
ICC-1122, which operates in exactly the same manner. The manual covers
basic and advanced operations, including square roots by Newton's
method, and gives examples of many types of practical business
calculations.

**
Schubert Pinwheel Calculator - Operating Instructions**

32 pages plus covers, fold-out, A5 size, comb bound.

This manual describes the Schubert models DRV, CRV, DW, and CW.
It covers all the basic operations and gives examples of more complex
business calculations. There are 4 pages of tables, including a table
for calculating by grosses. (Note: the original English-language manual
was printed in loose-leaf sections that could be assembled to suit
different models. Several pages mentioned in the index of this manual
are not actually present in the book. I have checked my copy of the
manual against two others from overseas, and all three have the same
index and exactly the same combination of pages).

**
Sharp Compet PC-1001 - Instruction Manual (1973)**

52 pages plus covers, fold-out, colour, 155x125mm (approx), comb bound.

This manual describes the operation and programming of the Sharp
PC-1001 desktop scientific calculator from 1973. The PC-1001 is an unusual
calculator, in that the circuitry is based on a general-purpose commercial
microprocessor system (the Rockwell PPS-4) rather than a dedicated
calculator chipset. The instruction manual gives descriptions and examples
of basic and scientific funtions, memory usage, and keystroke programming,
and includes a detailed Table of Accuracies.

**
Sumlock Electric and Duolectric Adding-Calculators - Service Manual**

103 pages plus covers, A4 size (originally 10" x 8"), comb bound.

This comprehensive service manual describes the
motor-driven Sumlock
calculators, both single and dual register, and applies also
to the identical machines
sold under the Comptometer brand. The first
section (30 pages) describes the construction and theory of operation
of the machines. The main section (60 pages) gives detailed procedures
for removal, replacement, and adjustment of all of the components and
assemblies. The final section describes service tools and common
problems. The manual is well illustrated with line drawings, annotated
photographs, and part names and numbers. The 10" x 8" original has
been reprinted on A4 paper. Several multi-page fold-outs have been
re-formatted into the body of the text, leaving occasional blank
or un-numbered pages.

**Operating Instructions for
Tallymaster Mark V Electric Home Adding Machine.**

12 pages including covers, spot colour, 8.5" x 5.5" (landscape), comb bound.

This little manual describes the controls of the Tallymaster
"Home Adding Machine", and gives basic instructions and examples for
addition and subtraction. It includes warranty and service information,
and a brief questionaire for the new "home" users.

58 pages including covers, A4 (originally 8.5x11), comb bound.

This service manual gives a very detailed and well-illustrated explanation of the mechanism and internal operation of the Victor 6 and 7 series (or 600/700 series) hand operated adding machines. The same basic mechanism was used in all of the Mehan Victors, including those with optional features such as direct subtraction, true negative totals, and electric motor drive.

**Victor Technical Documentation.**

A number of original Victor service manuals, parts manuals,
mechanism descriptions, and technical documents have been donated from
the estate of a former Victor calculator technician. The manuals cover
various models from the 5, 6, and 7 series, up to the automatic Premier
machines from the 1960s. Restorers with a specific interest in any of
these Victor machines can request further details via the
Enquiry Form.

**
Walther WSR160 Pinwheel Calculator - Sales Information**

6 pages, A4 size, loose leaf.

This is not an end-user manual, but rather a set of instructions
supplied to the Walther salesmen to assist them in presenting and
demonstrating the features of the machine. It covers all the controls
and operations of the WSR160, including back-transfer, negative
balances, short-cut multiplication, and extraction of square roots.

**
Walther WSR160 Pinwheel Calculator - Service Manual**

24 pages plus covers, A4 size, comb bound.

This factory service manual for the Walther WSR 110 and 160
pinwheel calculators contains detailed step-by-step instructions for
disassembling, reassembling, lubricating, and adjusting the machines.
There are 17 main illustrations showing all of the parts and operations
involved (with part numbers), and a detailed cross-sectional drawing.

**Walther Technical Documentation.**

A number of original Walther service manuals, parts manuals,
mechanism descriptions, and technical documents have been donated from
the estate of a former Walther calculator technician. The manuals cover
most of Walther's post-war mechanical calculators and adding machines,
and the first of the early-70s electronic calculators. Restorers with a
specific interest in any of these Walther machines can request further
details via the
Enquiry Form.

Please use the Enquiry Form for further information on any of these items.

Last Updated: 31 July 2018.

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