Difference between revisions of "UNIX Fourth Edition"

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(/* Possible alternative hardware for UNIX v4 from)
(Reverted mistake)
 
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Apparently, the only model of PDP-11 supported was the [[PDP-11/45]].
 
Apparently, the only model of PDP-11 supported was the [[PDP-11/45]].
 
"Amoug the new *goodies* are:
 
1) Separate I and D space for the resident monitor on 11/45s and 11/70s/"
 
 
https://www.spinellis.gr/pubs/jrnl/2016-EMPSE-unix-history/html/unix-history.pdf
 
  
 
A complete copy of Fourth Edition does not seem to be extant. [[The Unix Heritage Society|TUHS]] has a copy of the 'UNIX Programmer's Manual' and the [[source]] for what would become the V4 kernel. The main differences in this 'nsys' kernel compared to the later V4 kernel are the earlier V3 way of registering signal handlers, and a few not yet implemented system calls. Most importantly [[pipe]]s had not yet been implemented, making this kernel not fully functional even on a V3 system.
 
A complete copy of Fourth Edition does not seem to be extant. [[The Unix Heritage Society|TUHS]] has a copy of the 'UNIX Programmer's Manual' and the [[source]] for what would become the V4 kernel. The main differences in this 'nsys' kernel compared to the later V4 kernel are the earlier V3 way of registering signal handlers, and a few not yet implemented system calls. Most importantly [[pipe]]s had not yet been implemented, making this kernel not fully functional even on a V3 system.

Latest revision as of 02:49, 8 November 2025


Unix V4
Type: Multi-tasking, multi-user
Creator: AT&T/Western Electric
Architecture: PDP-11
Previous Version: V3
This Version: V4
Next Version: V5
Date Released: November, 1973


UNIX Fourth Edition (often referred to as UNIX V4 or V4 UNIX - 'Unix' was still normally given in all capital letters at this point in time) was an important early version of UNIX. It was the first version in which the kernel was written in C. It also had minor changes to the UNIX file system‎ (such as the ability of any inode to hold a device 'special file'), which left it in the form it retained until the BSD Fast File System.

Apparently, the only model of PDP-11 supported was the PDP-11/45.

A complete copy of Fourth Edition does not seem to be extant. TUHS has a copy of the 'UNIX Programmer's Manual' and the source for what would become the V4 kernel. The main differences in this 'nsys' kernel compared to the later V4 kernel are the earlier V3 way of registering signal handlers, and a few not yet implemented system calls. Most importantly pipes had not yet been implemented, making this kernel not fully functional even on a V3 system.

Possible Source(s)

"A tape-based piece of unique Unix history may have been lying quietly in storage at the University of Utah for 50+ years. The question is whether researchers will be able to take this piece of middle-aged media and rewind it back to the 1970s to get the data off."

"– The 4th Edition (November 1973 — Research-V4) contains only source markup for the manual pages: 18975 lines of troff code."

Research UNIX v4, dated to 1973: https://www.spinellis.gr/pubs/jrnl/2016-EMPSE-unix-history/html/unix-history.pdf

External links