Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!uwm.edu!zaphod.mps.ohio-state.edu!samsung!munnari.oz.au!murtoa.cs.mu.oz.au!ditmela!yarra!bohra!ejp
From: ejp@bohra.cpg.oz (Esmond Pitt)
Newsgroups: comp.unix.wizards
Subject: Re: bigger longs (64 bits)
Message-ID: <346@bohra.cpg.oz>
Date: 12 Feb 90 02:28:22 GMT
References: <11372@attctc.Dallas.TX.US>
Reply-To: ejp@bohra.cpg.oz.au (Esmond Pitt)
Organization: Computer Power Group, Melb, Australia
Lines: 15

In article <11372@attctc.Dallas.TX.US> markh@attctc.Dallas.TX.US (Mark Harrison) writes:
> 
>As Unix tries to get a larger share of the commercial market, We will see
>a need for storing numeric values with 18-digit precision, ala COBOL and
>the IBM mainframe.  This can be accomplished in 64 bits, and is probably
>the reason "they" chose 18 digits as their maximum precision.

According to a fellow who had been on the original IBM project in the
fifties, the 18 digits came about because of using BCD (4-bit decimal)
representation, in two 36-bit words.


-- 
Esmond Pitt, Computer Power Group
ejp@bohra.cpg.oz