On May 2, 2011, at 7:53 AM, Michael Watterson wrote:

> I think some 1960s mainframes actually had instructions to do it this
> way and then libraries for BCD arithmetic for large amounts of money.

IIRC, COBOL has BCD data types.  Or a decimal data type usually =20
implemented as BCD.  Or something.  It allows the language to do =20
"exact" operations on quantities of money, where the business types =20
apparently don't trust the vague inexactness of floating point.  So a =20
lot of CPUs tried to cater to the market by including hardware support =20
for such features.  Probably one of the things that the RISC =20
proponents pointed to and laughed about.

BillW

--=20
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