Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!lll-lcc!mordor!sri-spam!ames!amdcad!sun!gorodish!guy From: guy%gorodish@Sun.COM (Guy Harris) Newsgroups: comp.unix.wizards Subject: Re: Size of SysV "block" Message-ID: <23693@sun.uucp> Date: Thu, 16-Jul-87 20:17:58 EDT Article-I.D.: sun.23693 Posted: Thu Jul 16 20:17:58 1987 Date-Received: Sat, 18-Jul-87 11:05:20 EDT References: <218@astra.necisa.oz> <142700010@tiger.UUCP> <23436@sun.uucp> <518@cup.portal.com> Sender: news@sun.uucp Lines: 23 > No, the basic unit on a PDP 10 is not a "byte" it's a "word". I didn't say a byte was the *basic* unit of memory on the 10. It most definitely *did* have the notion of a "byte" in the instruction set, however (consider the Load Byte, Store Byte, Increment Byte Pointer, etc. instructions). Byte pointers indicated the size of the byte, so there was no single byte size in the hardware; I think the original software packed 5 7-bit bytes in a word, with one bit left over. > "Word" was universal nomenclature for unit of data before IBM introduced > the 360, the first byte-oriented machine. Not quite. The IBM 7030 or "Stretch" supported bit addressing; it used an 8-bit byte to store characters. I don't know if they used the term "byte", but it definitely supported access to bytes. (And, if you don't want to consider character-oriented machines like the 14xx series to be "byte-oriented", it's still byte-oriented; Stretch was not one of those machines.) I suspect there were other machines of the general flavor of the 360 out before the 360, as well. Guy Harris {ihnp4, decvax, seismo, decwrl, ...}!sun!guy guy@sun.com