Differences

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--- systems:2nd_edition [2023/05/20 16:50] – add revisions between manuals segaloco
+++ systems:2nd_edition [2023/05/23 08:17] (current) – hardware specifics segaloco
@@ Line 3: / Line 3: @@
 **Release Date:** June 12, 1972\\
 **Released By:** Bell Labs Research\\
-**Source Code: ** some source code is in the [[http://www.tuhs.org/Archive/PDP-11/Distributions/research/1972_stuff/|Unix Archive]], browsable in the [[http://www.tuhs.org/cgi-bin/utree.pl?file=V2|Unix Tree]]\\
+**Source Code: ** some source code is in the [[https://www.tuhs.org/Archive/Distributions/Research/1972_stuff/|Unix Archive]], browsable in the [[https://www.tuhs.org/cgi-bin/utree.pl?file=V2|Unix Tree]]\\
-**Documentation: ** [[http://www.tuhs.org/Archive/PDP-11/Distributions/research/1972_stuff/unix_2nd_edition_manual.pdf|2nd Edition man pages]]
+**Documentation: ** [[https://www.tuhs.org/Archive/Distributions/Research/Dennis_v2/v2man.pdf|2nd Edition man pages]]
-The second edition of Unix was developed for the PDP-11 at Bell Labs by Ken Thompson, Dennis Ritchie and others. It extended the First Edition with more system calls and more commands. This edition also saw the beginning of the C language, which was used to write some of the commands.
+The Second Edition of Unix was developed for the PDP-11/20 at Bell Labs by Ken Thompson, Dennis Ritchie and others. It extended the First Edition with more system calls and more commands. This edition also saw the beginning of the C language, which was used to write some of the commands.
-The code in the Unix Archive is only the source to some of the commands, some of the library functions, and the C compiler. The files in c/ come from the [[http://www.tuhs.org/Archive/Applications/Early_C_Compilers/last1120c.tar.gz|last1120c.tar.gz]] tape, and form a working C compiler for Second Edition Unix.
+The Second Edition, like the first, was only designed to run on the unprotected PDP-11/20 and requires the Extended Arithmetic Element to simulate some operations which would later be supported natively on the PDP-11/45 and other models. This would be the last PDP-11/20 unprotected version of UNIX, as the following Third Edition represents an intermediary PDP-11/45 assembly version of the system and the kernel is rewritten in C before the Fourth Edition.
+The code in the Unix Archive is only the source to some of the commands, some of the library functions, and the C compiler. The files in c/ come from the [[https://www.tuhs.org/Archive/Applications/Early_C_Compilers/last1120c.tar.gz|last1120c.tar.gz]] tape, and form a working C compiler for Second Edition Unix.
 The files in lib/ come from the libc.sa file which is on the last1120c.tar.gz tape, and form the C library for the compiler.
-The files in cmd/ are recreated from the text fragments found on the file [[http://www.tuhs.org/Archive/PDP-11/Distributions/research/1972_stuff/s1-bits.gz|s1-bits.gz]]. These were reconstructed by Doug Merritt and Warren Toomey, and form the source code to some of the commands in Second Edition Unix.
+The files in cmd/ are recreated from the text fragments found on the file [[https://www.tuhs.org/Archive/Distributions/Research/1972_stuff/s1-bits.gz|s1-bits.gz]]. These were reconstructed by Doug Merritt and Warren Toomey, and form the source code to some of the commands in Second Edition Unix.
 Another archive, [[https://www.tuhs.org/Archive/Distributions/Research/1972_stuff/s2-bits.tar.gz|s2-bits.tar.gz]], contains what appears to be a dump of the root filesystem of a Second Edition UNIX installation. The contents include binaries of three different formats: those that explicitly call brk upon start, those with a magic number of 405(8), the First Edition a.out(V) format, and those with a magic number of 407(8), the Second Edition a.out(V) format. These format discrepancies may imply the rough linking time of the various objects present.
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   * The UNIX Time-sharing System - D.M. Ritchie, K. Thompson
-For more information about Second Edition Unix, see [[http://cm.bell-labs.com/cm/cs/who/dmr/hist.html|The Evolution of the Unix Time-sharing System]] by Dennis Ritchie.
+For more information about Second Edition Unix, see [[https://www.bell-labs.com/usr/dmr/www/hist.html|The Evolution of the Unix Time-sharing System]] by Dennis Ritchie.