|
|
|
Modern Operating Systems by Herbert Bos and Andrew S. Tanenb...
Modern_Operating_Systems_by_Herbert_Bos_and_Andrew_S._Tanenbaum_4th_Ed.pdf
Showing 748 out of 1137
Modern Operating Systems by Herbert Bos and Andrew...
Modern_Operating_Systems_by_Herbert_Bos_and_Andrew_S._Tanenbaum_4th_Ed.pdf-M ODERN O PERATING S YSTEMS
Modern Operating Systems by Herbert...
Modern_Operating_Systems_by_Herbert_Bos_and_Andrew_S._Tanenbaum_4th_Ed.pdf-M ODERN O PERATING S YSTEMS
Page 748
SEC. 10.1
HISTORY OF UNIX AND LINUX
717
located on the fifth floor at Bell Labs. The Interdata was on the first floor.
Gener-
ating a new version meant compiling it on the fifth floor and then physically carry-
ing a magnetic tape down to the first floor to see if it worked. After several months
of tape carrying, an unknown person said: ‘‘You know, we’re the phone company.
Can’t we run a wire between these two machines?’’ Thus, was UNIX networking
born. After the Interdata port, UNIX was ported to the VAX and later to other com-
puters.
After AT&T was broken up in 1984 by the U.S. government, the company was
legally free to set up a computer subsidiary, and did so. Shortly thereafter, AT&T
released its first commercial UNIX product, System III.
It was not well received,
so it was replaced by an improved version, System V, a year later. Whatever hap-
pened to System IV is one of the great unsolved mysteries of computer science.
The original System V has since been replaced by System V, releases 2, 3, and 4,
each one bigger and more complicated than its predecessor.
In the process, the
original idea behind UNIX, of having a simple, elegant system, has gradually
diminished. Although Ritchie and Thompson’s group later produced an 8th, 9th,
and 10th edition of UNIX, these were never widely circulated, as AT&T put all its
marketing muscle behind System V.
However, some of the ideas from the 8th, 9th,
and 10th editions were eventually incorporated into System V.
AT&T eventually
decided that it wanted to be a telephone company after all, not a computer com-
pany, and sold its UNIX business to Novell in 1993.
Novell subsequently sold it to
the Santa Cruz Operation in 1995.
By then it was almost irrelevant who owned it,
since all the major computer companies already had licenses.
10.1.4 Berkeley UNIX
One of the many universities that acquired UNIX Version 6 early on was the
University of California at Berkeley. Because the full source code was available,
Berkeley was able to modify the system substantially. Aided by grants from ARPA,
the U.S. Dept. of Defense’s Advanced Research Projects Agency, Berkeley pro-
duced and released an improved version for the PDP-11 called
1BSD
(
First
Berkeley Software Distribution
). This tape was followed quickly by another, cal-
led
2BSD
, also for the PDP-11.
More important were
3BSD
and especially its successor,
4BSD
for the VAX.
Although AT&T had a VAX version of UNIX, called
32V
, it was essentially Ver-
sion 7.
In contrast, 4BSD contained a large number of improvements. Foremost
among these was the use of virtual memory and paging, allowing programs to be
larger than physical memory by paging parts of them in and out as needed. Anoth-
er change allowed file names to be longer than 14 characters.
The implementation
of the file system was also changed, making it considerably faster. Signal handling
was made more reliable.
Networking was introduced, causing the network proto-
col that was used,
TCP/IP
, to become a de facto standard in the UNIX world, and
later in the Internet, which is dominated by UNIX-based servers.
Ace your assessments! Get Better Grades
Browse thousands of Study Materials & Solutions from your Favorite Schools
Concordia University
Concordia_University
School:
Operating_Systems
Course:
Great resource for chem class. Had all the past labs and assignments
Leland P.
Santa Clara University
Introducing Study Plan
Using AI Tools to Help you understand and remember your course concepts better and faster than any other resource.
Find the best videos to learn every concept in that course from Youtube and Tiktok without searching.
Save All Relavent Videos & Materials and access anytime and anywhere
Prepare Smart and Guarantee better grades
Know more
Students also viewed documents
lab 18.docx
lab_18.docx
Course
Course
3
Module5QuizSTA2023.d...
Module5QuizSTA2023.docx.docx
Course
Course
10
Week 7 Test Math302....
Week_7_Test_Math302.docx.docx
Course
Course
30
Chapter 1 Assigment ...
Chapter_1_Assigment_Questions.docx.docx
Course
Course
5
Week 4 tests.docx.do...
Week_4_tests.docx.docx
Course
Course
23
Week 6 tests.docx.do...
Week_6_tests.docx.docx
Course
Course
106
