Re: Floating Decimal Package/Library?

[Darren New <dnew@san.rr.com>]

Marin David Condic wrote:
> 
> More out of curiosity than anything else: Some hardware supports Binary
> Coded Decimal (BCD) which was there to support Cobol-like numeric values.
> (Its been a while, but IIRC, the MC680x0 supported it.)

The 6502 let you add two BCD digits using a binary add, then had an
instruction (adjust decimal?) that would look at the half-carry flag and
convert it back to BCD with the appropriate carry bit set.

The Sigma-9/Xerox-560 had two optional units, the "scientific unit" (which
was a floating point coprocessor) and the "business unit" (which was a BCD
processor), either of which would be emulated if not present. The "business
unit" had built in instructions for things like COBOL's edit-byte-string.
Mmmmm... Text_IO.Editing in hardware!

-- 
Darren New 
San Diego, CA, USA (PST). Cryptokeys on demand.
** http://home.san.rr.com/dnew/DNResume.html **
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Things to be thankful for, #37:
   No sausage was served at the Last Supper.