Difference between revisions of "UNIX Second Edition"

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| creator = AT&T/[[Western Electric]]
 
| creator = AT&T/[[Western Electric]]
 
| year introduced = June, 1972
 
| year introduced = June, 1972
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| next version = [[UNIX Third Edition]]
 
| type = [[Multi-tasking]], [[multi-user]]
 
| type = [[Multi-tasking]], [[multi-user]]
 
| architecture = [[PDP-11 architecture|PDP-11]]
 
| architecture = [[PDP-11 architecture|PDP-11]]

Revision as of 01:56, 25 May 2022


Unix V2
Type: Multi-tasking, multi-user
Creator: AT&T/Western Electric
Architecture: PDP-11
Next Version: UNIX Third Edition
Date Released: June, 1972


UNIX Second Edition (often referred to as UNIX V2 or V2 UNIX - 'Unix' was still normally given in all capital letters at this point in time) was an early version of UNIX. There were 10 instances of UNIX running inside Bell at this point.

It still ran on the PDP-11/20 model of the PDP-11; the PDP-11/45 was apparently expected in the near future. The file system is almost identical to the V6 one; the only major differences are that i) the free blocks are stored as a bit array, rather than a list, and ii) device 'special files' are indicated by inode numbers below 41. (not via a flag in the 'mode' word in the inode, as later).

A copy of Second Edition does not seem to be extant. TUHS has the source code for some of its user code: an early version of the first C compiler (C was just being defined at the point in time), and many commands. The 'NIX Programmer's Manual: Second Edition' is also available.

External links