Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83 (MC830713); site log-hb.UUCP Path: utzoo!watmath!clyde!floyd!cmcl2!philabs!mcvax!enea!log-hb!hans From: hans@log-hb.UUCP (Hans Albertsson) Newsgroups: net.lang.c Subject: Re: pointer question Message-ID: <140@log-hb.UUCP> Date: Wed, 14-Mar-84 07:28:09 EST Article-I.D.: log-hb.140 Posted: Wed Mar 14 07:28:09 1984 Date-Received: Sat, 17-Mar-84 02:39:13 EST References: <7624@mgweed.UUCP> Organization: TeleLOGIC Nyn{shamn SWEDEN Lines: 19 [come & get it ] I know one machine where pointers are not just different length, but different data structures as well. I'm thinking of the DEC PDP-10, a 36-bit machine, ( VERY nice.. ) where most stuff gets put in an integral no. of full words, and a pointer to one of these objects is 18 bits, that is a Half-word. However, characters can have one of many representations, usually, but not always, 7 bits each ( other usual sizes are 5 or 6 bits ), and packed an integral no. of characters in a word, usually 5 7-bit char:s ( = 35 bits ) in a word. The left- over bit is ignored... This means that a "pointer" to a character string is a complex structure, containing A) the starting address, B) the "Byte Size" in bits plus the "Byte Number" you're presently looking at. It takes up MOST of a 36-bit word. Other examples probably exist.