Thread: Sharp Compet 18
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Old 8th Nov 2018, 11:46 am   #5
G6Tanuki
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Join Date: Apr 2012
Location: Wiltshire, UK.
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Default Re: Sharp Compet 18

Nice!

These 'adding machines' were often called 'totalisers' and you could set them to increment or decrement.

Example: switch set to increment. Enter first number, hit =, enter second number, hit = and the display shows the two numbers added together. Keep on entering numbers and hitting = and the total goes up appropriately.

Or: set switch to decrement. Enter first number, hit =, enter second number, hit = and the second number is subtracted from the first. Keep on entering numbers and hitting = to keep on subtracting.

The point of doing it this way is that you wouldn't hit + when you meant - or vice-versa: the + or - was set in advance of you doing your 'run'.

I remember them being used like this to check daily ledgers: you started off in increment-mode to add up all the day's transactions to get a total, saved the total, then flipped the switch to decrement and went back through the transactions subtracting them from the total you got first time round.

At the end of the second 'pass' you should see zero - anything else meant you had made an entry-error somewhere and had to do it all over again!
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