9 Dec
2010
9 Dec
'10
1:24 p.m.
Thanks much for the explanation. I notice that the
Toshiba BC-1212 has
one key labeled with both + and = so I'm guessing this was pretty common
in that time frame.
A number of machines had keys labelled '+=' amd '-=' or something
simialr. Addition and subtraction were effectively RPN :
2 + 3 = -> 2 += 3+=
7-5 = -> 7 += 5 -=
Multipliciation and division used normal infix notion with the '+=' key
being used for the 'equals'.
The Casio AL1000 (Commodore AL1000 in the States I think) and I believe
the AL2000 had something slghtly weirder. They used the += and -= as
above for addition and subtraction. Multiplication were infix, using +=
to give all digits of the product/quotient and -= to round it to the
number of digits set on the decimal places thumbwheel. There was also a
swtich for 5/4 rounding or truncation.
-tony