Calculating - Olivetti Summa 15
Back
Next
Sections
Museum Hold Tight! Photos
Walking Weather
Acorn Commodore Sinclair PCN
Calculating
Calculating
Introduction
In The Hand
Addiator
Addmaster
Arithma
Decimeter
Exactus
Reckoner
Addipresto
Bri Cal
Brunsviga
Contex A
Contex B
Olivetti 15 £sd
Olivetti 20 £sd
Olivetti Decimal
Plus
Victor
 
For an explanation of £sd money
see the Money page
 
 
 
 
 
 
Olivetti
Model   Summa 15
Maker   Olivetti
Origin   Italy
Date   1950s
Serial    
 
A version equipped with additional 10 and 11 keys for sterling £sd currency, but no halfpenny key.
 
A joystick selects subtraction, sub-total, total or number not to be included. The amount is entered, the joystick set if required and the handle pulled forward and released. The amount is printed on a paper roll, in black for individual amounts and in red for the total or sub-total, using a typewriter ribbon.
 
Pressing either the 10 or 11 key locks the keyboard to ensure that these values are registered only as pence.
 
Care must be taken to enter a zero in front of single digit shillings amounts after pounds have been entered by pressing the large black key (twice if no shillings). Any amount of shillings higher than 19 will be reduced to below 20, for instance 33 will register as 13.
 
The striped knob at the bottom right moves one notch to the left for each digit entered. Pulling this to the far right clears all numbers entered.
 
There is a sliding control above this which allows multiplication. This is achieved by entering an amount, setting the control to multiplication and pulling the handle the required number of times. There is a counter on the left of the keyboard so that the operator can see how many times the amount has been multiplied.
 
There is a slider to the left of the joystick to disable the entry of shillings and pence, calculations then being in whole numbers.
 
At the top right is a rotating manual paper feed control.
 
The original design dates from 1949 but the machine was probably made around 1960.
 
This machine is quite heavy.
     
Top of the Page