Medieval methods... (was Re: Got a question....PDP? VAX?)

From: <(>
Date: Wed Mar 17 08:43:24 1999

> I gather the machine had some sort of support for doing arithmetic on
> pre-decimalized currency, does anyone here know what that looked like?
> It wasn't explained very well in the book.

I don't know how the currency was handled on Leo, but as a reference for our
American friends I shall say a few words on British currency prior to 1971.

The basic unit was the pound. The symbol was the same as nowadays, viz. a
scripty capital L with two horizontal bars through it (though often only one bar
is written, for speed) On e-mail I generally use an ordinary L for pound (L
stands for Livre (french = pound))

King Offa (?9th century) fixed the value of a penny at 1/240 of a pound. Later
the shilling was fixed at 12 pence. (Pence is the plural of penny, in case you
hadn't worked it out. "Pennies" is a word coined much more recently (pun

So L1 = 20 s. (s stands for solidus (lat. = a silver coin of some sort) or sou
(Fr. = a coin worth not a lot))

1 s. = 12 d. (d stands for denarius (lat. = penny) or denier (fr. = penny))

Halfpence (pronounced ha'pence) were in use until 1969 (and re-introduced with
decimalisation in 1971).
Farthings (1/4 d) were in use at least until the mid 1940s, and may have been
required for Leo.

So to computerise the currency you probably need:

A field for whole pounds
A field for shillings (up to 19 with a carry at 20)
A field for pence (up to 11 with a carry at 12)
A field for farthings or ha'pence (up to the obvious numbers thereof)

It would not likely be possible to ignore the fractions of pence, since even as
late as the 1950s 1/2 d had a reasonable purchasing power, perhaps equivalent to
one US dime today.

Also, just as they do today, vendors loved prices ending ...nineteen shillings
and elevenpence ha'penny.

Received on Wed Mar 17 1999 - 08:43:24 GMT

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