Here is a collection of of old DECtapes given to Warren Toomey by Dennis Ritchie in 1997. The 'bits' file is the original tape image, which is in either 'tp' or 'tap' format. The contents of each tape is summarised in a 'list' file . The contents have been extracted (if possible) into a 'tp' directory: many thanks to Angelo Papenhoff who did to work to extract the contents of the tapes. Dennis' original description of the contents of the tapes is below. ---- The files here were read from old DECtapes made in the early 1970s. Paul Vixie and Keith Bostic unearthed a DECtape drive and made it work, we unearthed the tapes. The tapes were written in either the 'tap' or 'tp' format, which are similar in that they have a directory of up to 192 entries at the start with names and other information including the size and tape address of the files. 'tp' was the later format, and was in use by November 1973, the date of the 4th edition manual. With `tap', the times associated with the files were recorded in pre-modern units: sixtieths of a second, from an origin that changed. The first three editions of the manual had BUGS sections noting that 32 bits can represent only about 2.5 years in this unit, and this implied continuing crises as the time overflowed. I believe that the change to use seconds for Unix time took place along with the change to the C version of the operating system, which occurred about the end of the summer of 1973, and also that the change from `tap' to `tp' took place at the same time. (This is consistent with the dates of the 3rd and 4th edition manuals). Thus the dates recorded with the `tp' tapes probably correspond reliably to the modification dates of the files at the time of saving them (of course, this gives only a upper bound on their creation, since they might have been copied or trivially touched just before saving them). Recovering the proper dates for the `tap' tapes is less reliable, because there was at least one change of epoch (from 1971 to 1972) during the period they could possibly have been produced. I believe that the 1972 epoch is most likely the correct one for the tapes here. apl Ken's apl program, together with his rendition of astro (translated from Morris's Fortran). Probably OK dates, 1975-76. config Ken's program for configuring PDP11s. It told you price, maintenance, checked for bus loading. Interesting for DEC price lists in 1974. dmr Random stuff from my directory. Most probable dates: 1972. The `paper' directory contains a version of the original SOSP Unix paper (haven't compared it with the CACM version). cgd appears to be an experiment in converting Fortran threaded code to machine language, using a warmed over version of the earliest C code generator. It's written in NB, not C. fd is some fortran programs, in particular a polynomial root-finder I found somewhere. aman is some version of the PDP-11 assembler manual. fd is a fortran program for plotting functions of 2 variables. notes1 and notes2 are evidently notes I made for myself for a talk on unix. They are quite interesting. tty.s is evidently the terminal processing routine for an assembly-language version of unix. note that it handles IBM 2741 terminals with two kinds of typeballs (938 and correspondence). crypt.c encrypts using a variant of the Hagelin machine. pig.b is an interesting artifact: it is a B program that echoes what you type in Pig latin. (Incidentally, there is a translation of this program into C, dated 1978, in a subdirectory that still spins on a disk attached to the Unix machine where I get my mail.) dmr2 the let directory contains drafts of a bunch of letters to people who asked about unix in early days. (lett6 is to andy tanenbaum). The let directory contains drafts of a bunch of letters to people who asked about unix in early days. (lett6 is to andy tanenbaum). Other bits: restric discusses some early thoughts about types in C. I don't know who it was addressed to (perhaps even to myself). ct is an even briefer list about what I though was important. iosys is a manual for writing system device drivers. e-pi Our programs to compute e and pi to a million places. The one for e worked; it took some months on a time-shared PDP-11 without memory mapping. Incidentally the J directory name is correct: this sequence printed the greek letter pi on a Teletype model 37. Plan 9 won't let me create this. It wants me to use Unicode! games Ken's work on various games. Check out chomp/c0.c, which has a briefly-existing form of structure declaration using parentheses instead of braces. ken check out the values of the AT&T Savings plan in the early 70s (plan), and what interested Ken's son (corey/*) then. ken-du Here, you can read our wtmp files from 1974 and 1975. ken-sky A bunch of interesting old ken stuff (eg a version of the units program from the days when the dollar fetched 302.7 yen) last1120c The source for a version of C that compiled for the PDP-11/20. It didn't have structures, it didn't have #define, and pointers were declared p[]. But look! The initialization routine says init("float", 2); init("double", 3); /* init("long", 4); */ init("auto", 5); init("extern", 6); nsys If the decoding of the date on the tape is correct (Aug 1973), this is the source for the earliest C version of Unix likely to be recovered. `nsys' meant the C version rather than the assembly version, and Aug 73 is plausible for a running instance of this system. prestruct-c This is approximately the same era as `last1120c,' but 6 months later; despite the name, this compiler now handles structures. (The struct keyword has displaced `long' as keyword number 4!) The name of the tape indicates that the state of the compiler was saved just before converting it to use structures inside itself. The compiler is much less complete--just the c??.c files, not the tables for code generation. s1 I haven't cracked this yet. s2 Is not source, but a dump of (parts of) /bin, /etc, /usr/lib, and bits of a few other directories. Caution! The tape uses absolute pathnames, and is dangerous to extract unless you want to install old PDP-11 binaries. (tap format). sys-dsu This system didn't come directly from us. After poking around it for a while I found a file containing this (in cr.h): /***************************************************************** ** ** ** U C L A Data Secure Unix ** ** ** ** Copyright 1977 ** ** ** ** Mark Kampe, Charles Kline, Gerald Popek, Evelyn Walton ** ** ** *****************************************************************/ So, it appears that `dsu' is `data-secure unix' and this is a record of one of the early security projects! They must have sent it to us. Might be fun to examine it; I suppose we should tell Gerry Popek of its existence. unix This is probably a `boot' tape; it has binary images of the system and some raw utility programs for use when booting (memory testers, loaders for diagnostics, and the like).