I ran some experiments on BeebEm to see how expensive it is to deal with floating point values.

Note that the code in the 4.32 version of BBC BASIC is a lot quicker than that in earlier versions: it takes 0.8 milliseconds to multiply two 5-byte numbers on a 3MHz 65C02, compared to 1.2 milliseconds in version 3.

The relative cost of trig functions is improved too: I think the older basic uses a polynomial for each, whereas the newer one uses(*) the ratio of two polynomials, which gets more accuracy for less work. The following figures are calculated as an equivalent number of multiplies:



Edit: Basic2 source is here or here

Edit: (*) actually uses some other trick - continued fraction?? See here although it mostly duplicates the basic4 documentation linked above.

Edit: repaired some broken links: beebwiki is now found at http://beebwiki.mdfs.net