Path: csiph.com!usenet.pasdenom.info!aioe.org!.POSTED!not-for-mail From: glen herrmannsfeldt Newsgroups: comp.lang.java.programmer Subject: Re: Teaching kids to program (in Java) Date: Sun, 6 May 2012 17:10:54 +0000 (UTC) Organization: Aioe.org NNTP Server Lines: 26 Message-ID: References: <71igo75jrn2rodtmtv8qnc9q6hrl0n6lkt@4ax.com> <4f8e22d5$0$293$14726298@news.sunsite.dk> <4f8f4c40$0$291$14726298@news.sunsite.dk> <20638428.276.1334951022461.JavaMail.geo-discussion-forums@pbcsx5> <56h3p7phgturh7hkno6k1q9pfohfdi5b6j@4ax.com> <4fa5c494$0$294$14726298@news.sunsite.dk> NNTP-Posting-Host: H0vc4U5LIRkRHNPyGCs2dA.user.speranza.aioe.org X-Complaints-To: abuse@aioe.org User-Agent: tin/1.9.6-20100522 ("Lochruan") (UNIX) (Linux/2.6.32-5-amd64 (x86_64)) X-Notice: Filtered by postfilter v. 0.8.2 Xref: csiph.com comp.lang.java.programmer:14340 Martin Gregorie wrote: (snip) > So, back when C was specified, it made sense to have both hex and octal > bit representations because it was being used on both byte and word > oriented hardware (didn't some early DEC kit use word and character > lengths that were multiples of 3 rather than 4?) but now, with the > almost universal adoption of byte-oriented architectures there's > little reason, other than historic, to use octal notation. Before VAX, everything DEC was octal. There were machines with 12 bit and 36 bit words. The PDP-11 used 16 bits, but the instruction fields were divided up such that octal made them more readable. Much of the PDP-11 software uses Radix 50, which is actually base 40 because the 50 is in octal. (Three characters per word.) With VAX, they went hex, though octal was still supported. Stories are that DEC published a calendar with the dates in hex in the year before VAX was released. Instruction fields are in multiples of four bits. The DUMP commands prints ASCII and hex. (The hex going right to left, so that little endian values can be read correctly.) -- glen