Quoting http://www2.hursley.ibm.com/decimal/ :

"Most computers today support binary floating-point in hardware. While
suitable for many purposes, binary floating-point arithmetic should not
be used for financial, commercial, and user-centric applications or web
services because the decimal data used in these applications cannot be
represented exactly using binary floating-point. (See the Frequently
Asked Questions pages for more explanation and examples.)

The problems of binary floating-point can be avoided by using base 10
(decimal) exponents and preserving those exponents where possible. This
site describes a decimal arithmetic which achieves the necessary results
and is suitable for both hardware and software implementation. It brings
together the relevant concepts from a number of ANSI, IEEE, ECMA, and ISO
standards, and conforms to the proposed decimal formats and arithmetic in
the current draft of the ongoing IEEE 754 revision.

Notably, a single data type can be used for integer, fixed-point, and
floating-point decimal arithmetic, and the design permits compatible
fixed-size and arbitrary-precision implementations. For the background
and rationale for the design, see Decimal Floating-Point: Algorism for
Computers, Cowlishaw, 2003, 16th IEEE Symposium on Computer Arithmetic."

-- 
Sean
sean at manybits.net

On Fri, 17 Sep 2004, Tim Rowledge wrote:

> An old colleague of mine and fellow IBM Fellow ('cept that he's the
> full spec, crowned in glory variety rather than the pondscum variety I
> was) Mike Cowlishaw had/has a non-trivial involvement in this stuff.
> I'm pretty sure he told me about making hardware for it.
>
> tim
> --
> Tim Rowledge, tim at sumeru.stanford.edu, http://sumeru.stanford.edu/tim
> Useful Latin Phrases:- Mellita, domi adsum. = Honey, I'm home.
>