Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!psuvax1!rutgers!att!cbnewsm!lfd From: lfd@cbnewsm.att.com (leland.f.derbenwick) Newsgroups: comp.lang.c Subject: Re: a style question Summary: Development of C... Message-ID: <1990Oct12.225501.15701@cbnewsm.att.com> Date: 12 Oct 90 22:55:01 GMT References: <1990Oct6.231143.28186@zoo.toronto.edu> <65263@lanl.gov> Distribution: na Organization: AT&T Bell Laboratories Lines: 49 In article , meissner@osf.org (Michael Meissner) writes: > In article peter@ficc.ferranti.com (Peter da Silva) writes: > > [ ... ] > | In article <65263@lanl.gov> jlg@lanl.gov (Jim Giles) writes: > | > In the _very_ early days of C, it may have compared well to the PDP-8 > | > assembler - mostly because it way practically an upward compatible > | > extension of that assembler. > | > | Talking of contrary to observed fact: the PDP-8 had no part in the > | development of the C programming language. Perhaps you're thinking > | of the PDP-11. > > Or if you know your UNIX pre-history, the PDP-7. Bzzzt. Thank you for playing. To quote Ritchie, Johnson, Lesk, and Kernighan ("The C Programming Language", _Bell System Technical Journal_ Vol. 57, No. 6, July- August 1978, p. 1991): C was originally written for the PDP-11 under UNIX... and to quote Ritchie ("The Evolution of the UNIX Time-sharing System", _AT&T Bell Laboratories Technical Journal_ Vol. 63, No. 8 Part 2, p. 1591-2): Every program for the original PDP-7 UNIX was written in assembly language...[description of Thompson creating B on the PDP-7 omitted] When the PDP-11 arrived, B was moved to it almost immediately. ...Thus, in 1971, work began on what was to become the C language... (BTW, the PDP-11 purchase was justified for use as a word-processing system for the legal department: for all that people complain about how "obscure" and "difficult" the Unix system is, it was being used routinely by a group of secretaries in 1971.) One of the main heritages of the PDP-11 is that most people use the constructs "*p++" and "*--p" more often than "*++p" and "*p--"; for char or int arguments, the first two could be compiled into a single PDP-11 instruction, while the other two required an extra instruction. (Of course, if C were really intended only as a structured assembler, the two forms that didn't conform to the instruction set would never have been included.) -- Speaking strictly for myself, -- Lee Derbenwick, AT&T Bell Laboratories, Warren, NJ -- lfd@cbnewsm.ATT.COM or !att!cbnewsm!lfd