----- Original Message -----=20
From: "Olin Lathrop" <olin_piclist@embedinc.com>
To: "Microcontroller discussion list - Public." <piclist@mit.edu>
Sent: Tuesday, May 03, 2011 8:22 AM
Subject: Re: [PIC] Biinary to BCD


> 'William Chops" Westfield ' <westfw@mac.com wrote:
>> IIRC, COBOL has BCD data types.  Or a decimal data type usually
>> implemented as BCD.  Or something.  It allows the language to do
>> "exact" operations on quantities of money, where the business types
>> apparently don't trust the vague inexactness of floating point.
>
> That's a argument for integer versus floating point, not for a BCD
> representation of that integer in particular.  What you really need is=20
> extra
> wide integer support.  32 bits is not enough dynamic range when in units=
=20
> of
> cents.

BCD made (makes?) sense when the ratio of (human-readable) input-output to=
=20
calculations was (is?) rather high.

It takes quite a bit of crunch to convert between BCD and binary.

BCD can certainly make sense in a microcontroller environment just to avoid=
=20
the conversion overhead.

In contrast, if my memory doesn't fail me, the decimal data types in SQL=20
server are actually stored as binary with an implied decimal point.

-- Bob Ammerman

--=20
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