Re: S/360

glen herrmannsfeldt wrote:
> James J. Weinkam wrote:
> 
> (snip regarding mantissa)
> 
>> In my opinion, the best practice is to use the terms significand and 
>> exponent and avoid the misleading use or mantissa and characteristic, 
>> but it is impossible to undo history so we will no doubt continue to 
>> see the misuse of mantissa and characteristic.
> 
> 
> I have read discussions about logarithmic systems where instead of 
> fraction (or significand) and exponent the mantissa and characteristic 
> of the log of the desired value are stored.  This makes multiply easy 
> and add hard, though, but in that case mantissa does describe the stored

> value.
> 
> -- glen
> 
Well, if it really is a logarithmic system, I suppose the terms
characteristic 
and mantissa are appropriate, but can you give a reference?

The question I have is why anyone would want to do this.  In Napier's
time, 
logarithms were used to reduce multiplication to addition when there were
no 
mechanical or electronic calculators.  Now that we have them, what's the
point 
for that purpose?

Of course the logarithm and exponential functions have numerous other
useful 
applications, but that's another story.