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CS 8422 Advanced Computing Systems, Dr. Hoganson
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CS8422 Computing Systems
Dr. Ken Hoganson
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Copyright © 2003, Dr. Ken Hoganson
CS 8422 Advanced Computing Systems, Dr. Hoganson
History/Development
And Demise of CP/M
Richard Iwezulu
CS 8422, Spring 2003
Copyright © 2003, Dr. Ken Hoganson
History of CP/M
CS 8422 Advanced Computing Systems, Dr. Hoganson
• What is CP/M?
• Developed in 1973 by Gary Kildall
• Invented as a workaround
• Based on Intel 8080 processor
CP/M is an acronym for Control Program for Microcomputers. It is an
operating system for 8 bit computers.
Kildall needed an OS for a personal computer to test the compiler he was
developing for Intel. He did not like the long commute to use the mini
computer at Intel.
Copyright © 2003, Dr. Ken Hoganson
History of CP/M
CS 8422 Advanced Computing Systems, Dr. Hoganson
• Originally developed for machines with only
floppy drives and 64K memory
• Intel saw no potential in an OS for personal
computers and declined to market it
• Intel allowed Kildall to keep the rights to the
new software
Kildall gave Intel the OS he developed for them but they were not
convinced that
people would want little computers for themselves.
Kildall kept the rights to his software and decided to market it
himself. He formed Digital
Research which was bought by Novell soon after Kildall died in 1994.
Copyright © 2003, Dr. Ken Hoganson
History of CP/M
CS 8422 Advanced Computing Systems, Dr. Hoganson
• Entire OS took only 8K of computer’s memory
• 3 main versions – 1.4, 2.2 and 3.1
• 8 character file names with 3 character
extensions
• The first 36 MS-DOS system calls mirror CP/M
CP/M proved to be very powerful with little hardware demands.
CP/M bears a lot of familiarity with MS-DOS, they both have the same 8
character file
names with 3 character extensions.
Copyright © 2003, Dr. Ken Hoganson
Development of CP/M
CS 8422 Advanced Computing Systems, Dr. Hoganson
• Does not require a disk, monitor or keyboard
to operate
• Created a BIOS module for compatibility
• OS was separated into 3 logical pieces:
Console Command Processor (CCP)
Basic Disk Operating System (BDOS)
KildallBasic
separated
parts of his OS that
addressed
the specific format of
Input/Output
System
(BIOS)
diskettes and
placed them in a separate module called the BIOS, thereby achieving
cross-platform
acceptance for his OS.
Copyright © 2003, Dr. Ken Hoganson
Development of CP/M
CS 8422 Advanced Computing Systems, Dr. Hoganson
• Version 2.2 added support for up to 8 drives at
8MB per drive
• Version 2.2 was the basis of MSDOS and
version 3.1 evolved into DRDOS
• Version 2.2 dominated micro computing
• 16 bit version was CP/M-86 based on Intel
8086
processors
In 1978
alone,
version 2.2 was sold on more 500,000 computers and by
1980 it seemed
hardly conceivable that any other OS would ever be used on Intel-based
computers.
Copyright © 2003, Dr. Ken Hoganson
Development of CP/M
CS 8422 Advanced Computing Systems, Dr. Hoganson
• Users could modify OS themselves
• OS was very cheap
• Available software included Calc, WordStar
and dBASE II
• 15 second boot up time
Users could modify OS to suit themselves or meet their company’s needs.
Both OS and hardware was relatively cheaper than available alternatives.
Boot up was very fast.
Copyright © 2003, Dr. Ken Hoganson
Development of CP/M
CS 8422 Advanced Computing Systems, Dr. Hoganson
• BIOS allowed programmers to write their
routines to a set of subprograms at a time
when industry standards did not exist for
different machines
• CP/M was very stable and bug-free
• Drive letters could be assigned according to
the user’s preference
BIOS solved the headache of writing different machine code for all
kinds of hardware
when writing software programs for the OS.
User’s had the flexibility of assigning drive letters up to “P” on any
drive as they wished.
Copyright © 2003, Dr. Ken Hoganson
Demise of CP/M
CS 8422 Advanced Computing Systems, Dr. Hoganson
• Programs and private data had to be carried
around on 5-1/4” floppies
• CP/M had no network capabilities
• Digital Research was slow to incorporate 16
bit technology
CP/M did not harness the advantages a hard drive gave a computer
until they had lost
most of their market share.
Digital Research felt that 1 MB of memory - which Intel’s new 16 bit
chips were capable
of - was more than anyone could figure out a use for on a PC.
Copyright © 2003, Dr. Ken Hoganson
Demise of CP/M
CS 8422 Advanced Computing Systems, Dr. Hoganson
• OS depended on utilities to do some basic
operations like file copying
• CP/M did not have a full screen editor
• Arcane command line syntax
• MSDOS commands were more user friendly
CP/M needed utilities for operations like long directory listings and
file copying.
CP/M did not address screen formatting lacked a full screen editor, it
was so bad that
users started using WordStar to do the text editing.
Copyright © 2003, Dr. Ken Hoganson
Demise of CP/M
CS 8422 Advanced Computing Systems, Dr. Hoganson
• 16 bit 8088 processor made it easier to write
better programs in less time
• IBM used an open architecture like CP/M,
creating a new standard based on 16 bit
technology with MS-DOS
• Running programs on 16 bit CP/M meant
transferring control back and forth from 16 to
it’s
native
8 bit machine
making it
Many
hardware
manufacturers
jumpedlanguage,
on the IBM bandwagon
creating
a new 16 bit
slow
standard and leaving CP/M behind
Using 16 bit CP/M was like having two computers that transferred
requests and
information back and forth
Copyright © 2003, Dr. Ken Hoganson
Demise of CP/M
CS 8422 Advanced Computing Systems, Dr. Hoganson
• Kildall missed his opportunity to sign up with
IBM and they went to Bill Gates for an OS for
their new “PC”
• By the time CP/M-86 was released, MS-DOS
was firmly entrenched on IBM PC’s
• Why is the string in function 9 terminated by a
dollar sign?
IBM felt snubbed when they approached Kildall for an OS and he was
not there to meet
them
Whenever approached about the rumor that MS-DOS was copied
from CP/M, Kildall
always had interviewers ask Bill Gates that question “…because he
[Gates] can’t answer,
Copyright © 2003, Dr. Ken Hoganson
only I know that!”
CS 8422 Advanced Computing Systems, Dr. Hoganson
C/pm history
Wei-Hsiang Peng
CS 8422, Spring 2003
Copyright © 2003, Dr. Ken Hoganson
CP/M?
CS 8422 Advanced Computing Systems, Dr. Hoganson
• What is CP/M ?
Control Program for Microcomputers
alternatively Control Program / Monitor

Control Program for Microcomputers. An operating system that manages
computer resources and provides a standard systems interface to software
written for a large variety of microprocessor-based computer systems.
It's an operating system for 8-bit computers. It looks rather like DOS to use
(only not so user-friendly);
Copyright © 2003, Dr. Ken Hoganson
BIRTH-1
CS 8422 Advanced Computing Systems, Dr. Hoganson
• The creator of CP/M- Gary Kildall
• Kildall & Intel
• How Kildall created CP/M
•
Gary was the first person to interface a disk system to a microcomputer and create an operating
system for it. He changed what had previously been a circuit designed for process control
applications into a fully functional computer. The world changed dramatically because of his
work.
•
in 1975 ,Gary Kildall was working as a consultant to Intel (inventors of the 8080 chip which
at that time powered the majority of non-Apple microcomputers).
Kildall's task at Intel that year was to design and develop a language called PL/M (
Programming anguage / Microcomputers ) for the 8080 chip, to be used as a systems
development language. At the time, the chips themselves barely existed and Intel was just
then starting to design a computer system that used the 8080. The plan was for Gary to use
the 8080 emulator Intel had running on their big PDP-10 minicomputer. The only 8080based computer Intel had available was called "Intellec-8", but it didn't have any software
or disk storage attached to it. So Kildall obtained a used test floppy drive free from Shugart
Associates, attached it to the Intellec-8 with a controller designed by his friend John
Torode, and wrote a primitive operating system for it which he called CP/M.
Copyright © 2003, Dr. Ken Hoganson
BIRTH-2
CS 8422 Advanced Computing Systems, Dr. Hoganson
• 1975 - CP/M version 1.0
• 1976 – The growth of “8080 chips” business
• “IMSAI” & Kildall
•
•
•
•
CP/M was developed on Intel's 8080 emulator under DEC's TOPS-10 operating
system, so naturally many parts of CP/M were inspired by it, including the
eight character filenames with a three-character extension that every MSDOS/Windows 3.X user still lives with today.
By the end of 1975, Kildall at last had CP/M version 1.0 ready and had started
on PL/M, but Intel was no longer interested in the systems development
language by that time. Gary offered CP/M to them, but the company saw no
potential in it and declined to market it.
By 1976, the world was moving onward and upward. Intel was so busy selling
bucketloads of 8080 chips to the many small and growing computer
manufacturers that it didn't miss a dubious opportunity to get into the
software business one bit. Many of these new companies had neither the time
nor expertise to write their own proprietary operating systems
A company called IMSAI, which built a very successful 8080-based system, had
just started marketing their own floppy disk system, and needed some
software to use it -- fast. They heard about Kildall and his CP/M, and contacted
him.
Copyright © 2003, Dr. Ken Hoganson
BIRTH-3
CS 8422 Advanced Computing Systems, Dr. Hoganson
• Kidall solved the “incompatible ”problem with
“BIOS”
• CP/M
• Kildall formed the company “DR”
•
•
•
IMSAI wanted CP/M, and Kildall wanted to sell it, but the trouble was CP/M was written to
only use "standard" IBM-compatable soft-sectored floppy disks. They had a different,
incompatible flavor of floppy. At this point, most ordinary programmers would simply have
changed the operating system to use the different format and sold it, but Gary Kildall had a
better idea. What he did was separate out the parts of CP/M version 1 that addressed the
specific format of the diskettes, and placed them in a separate module he called the BIOS,
for Basic Input/Output System. That way, the system could easily be adapted to new
hardware without having to rewrite or even revise the complex heart of the software.
Other new hardware startups need not write their own software, they could buy CP/M and
adapt it themselves to their unique hardware. Further, because CP/M operated the same
way on every 8080-based computer, other software developers were also relieved of the
necessity of adapting their software products to each new machine -- they could write to be
compatable with CP/M, and let it take care of the details of doing the I/O.
Kildall was an engineer, not a businessman, but he could recognize a gold mine when he
saw one. He rapidly formed his own company, called Intergalactic Digital Research, to
market and further develop CP/M and other products such as his abandoned PL/M.
Copyright © 2003, Dr. Ken Hoganson
LIFE-1
CS 8422 Advanced Computing Systems, Dr. Hoganson
• CP/M 2.0 was consisted by 3 parts
-CCP
-BDOS
-BIOS
• CP/M 2.0  CP/M 2.1  CP/M 2.2
•
•
The DR company's seminal product was CP/M 2.0, which fully separated the
three components of the operating system into logical pieces: the CCP (console
command processor); the BDOS (Basic Disk Operating System); and the BIOS.
Only the BIOS need be provided by anyone to get CP/M running on a new
machine, the CCP and BDOS would be unchanged.
CP/M 2.0 was quite buggy, and was quickly followed by 2.1 as a fix-up release.
However, 2.1 was limited in its internal capacity to small floppy drives, and by
1977, hard drives were coming on the scene. CP/M version 2.2 added
expanded disk formatting tables which could allow access to up to 8 (eight)
megabytes per drive in up to 8 (eight) total drives. It was version 2.2 that
became the megahit that dominated microcomputing almost from its outset.
Copyright © 2003, Dr. Ken Hoganson
LIFE-2
CS 8422 Advanced Computing Systems, Dr. Hoganson
• Reasons why CP/M succeed
• Popular programs of CP/M
• How many computers installed CP/M by 1980?
•
•
•
It was CP/M's adaptability that gave it appeal and launched it on the road to success, but
any operating system that had that characteristic might have succeeded in a similar way,
given the right timing and some luck. But CP/M was more than just lucky -- it was good. It
packed a surprizing amount of power in a tiny package, and did so in a simple, clean logical
way.
The first real "killer app" for CP/M was probably WordStar, a word processing program that
became very widely used. Also famous was the first microcomputer database application,
dBASE II. These and many, many other applications and utilities eventually made CP/M a
useful tool for a wide range of ordinary people.
By 1978, CP/M 2.2 had been ported to nearly every 8080 and Z80 based microcomputer
built. In the end, more that 500,000 computers would be sold with CP/M as their operating
system. It so dominated the microcomputer world by 1980 that it seemed hardly
conceivable that any other operating system would ever be used on Intel-based computers.
Copyright © 2003, Dr. Ken Hoganson
DEATH-1
CS 8422 Advanced Computing Systems, Dr. Hoganson
Crossroad of the computer history:
• The direction to R&D of CP/M—8080 chips, in
1981
• The computer giant-- IBM’s choice—8088
chips, in1981
•
•
By 1981, the apogee of the CP/M orbit, a new generation of Intel
microprocessors was on the horizon -- the 8086 and 8088 16-bit chips, which
could address an incredible 1 megabyte of memory. This seemed at the time
more than anyone could ever figure out a use for, so Digital Research focused
much of their attention on producing CP/M 3.0 for the dominant 8080/Z80
platform. There were plans of course to port CP/M to the new 16-bit chips with
a version called CP/M-86, but it was not a priority at the time.
But IBM planned on entering the microcomputer market in a serious way in
1981, and the computer giant had its own priorities and a great deal of money
and marketing power to back them up. IBM chose the new 8088 chip as the
heart of their new PC, and of course they needed an operating system to run on
it. Instead of writing their own, as they generally did with a new machine, time
and the demands of the market led them to Digital Research's door to license
the ubiquitous CP/M for the new IBM-PC.
Copyright © 2003, Dr. Ken Hoganson
DEATH-2
CS 8422 Advanced Computing Systems, Dr. Hoganson
• Kildall missed the contract of IBM
• IBM’s another company choice
• The IBM & Microsoft joined
•
As the now-famous story goes, Gary Kildall was not there to open
that door when IBM came calling -- an avid amateur pilot, he was
flying his private plane on a business trip to the Bay area. His wife
and business partner, confronted with IBM's imposing code of
secrecy and nondisclouse agreements, refused to sign even
enough for talks to begin. Rebuffed by what they considered
arrogance, the IBMer's went elsewhere -- to Seattle and another
small young software firm called Microsoft. A deal was struck
there, and as they say, the rest is history.
Copyright © 2003, Dr. Ken Hoganson
Versions of CP/M
CS 8422 Advanced Computing Systems, Dr. Hoganson
• CP/M came in three main versions :
- v1.4
- v2.2 was the basis of MSDOS
- v3.1 evolved into DRDOS and OpenDOS /
DR-DOS.
• There were also 8086 and 68000 versions of
CP/M. CP/M-86 evolved into DOS Plus,
• In
1979, DR released version
which
soon was followed by CP/M 2.2. This
Concurrent
DOS2.0,
and
REAL/32.
•
version was installed most worldwide, as it offered high performance together with
little memory requirements.
CP/M version 3.0, also called CP/M Plus, was not released before 1982.
Unfortunately this was too late, since one year before the IBM-PC had begun its
triumphant advance. Besides the AMSTRAD CPC 6128 and their PCW (both using
CP/M 3.1*) you can find CP/M Plus also on the C-128 ( CP/M 3.0*).
Copyright © 2003, Dr. Ken Hoganson
CP/M Memory Organization-1
CS 8422 Advanced Computing Systems, Dr. Hoganson
• CP/M is logically divided into four parts:
BIOS - the basic I/0 system for serial
peripheral control
BDOS - the basic disk operating system
primitives
•
•
•
CCP
- the console command processor
TPA
- the transient program area
The BIOS and BDOS are combined into a single program with a common entry
point and
referred to as the FDOS.
The CCP is a distinct program which uses the FDOS to provide a humanoriented
interface to the information which is cataloged on the diskette.
The TPA is an area of memory (i.e, the portion which is not used by the FDOS
and CCP) where various nonresident operating system commands are executed. User programs also
Copyright © 2003, Dr. Ken Hoganson
execute in the TPA.
CP/M Memory Organization-2
CS 8422 Advanced Computing Systems, Dr. Hoganson
•
fbase: FDOS(BDOS+BIO
cbase:
tbase:
boot:
•
S)
CCP
TPA
System
Parameters
The BIOS and BDOS are logically combined into a single module with a common entry point
and referred to as the FDOS. The CCP is a distinct program that uses the FDOS to provide a
human-oriented interface with the information that is cataloged on the back-up storage
device. The TPA is an area of memory, not used by the FDOS and CCP, where various
nonresident operating system commands and user programs are executed. The lower
portion of memory is reserved for system information and is detailed in later sections.
Copyright © 2003, Dr. Ken Hoganson
CP/M Plus COMMANDS
CS 8422 Advanced Computing Systems, Dr. Hoganson
There are some CP/M Plus commands listed.
• TYPE
• DIR
• SHOW
• DATE
• ERASE
• RENAME
• DISCKIT
• PIP
•
•
•
•
•
•
•
•
Type-shows a named file on the screen, waiting for a key between pages.
DIR-find the names of disk files.
SHOW-tells you the amount of space in a drive.
DATE-lets you read and set the date and time, used to mark files.
ERASE-remove files from a disk.
RENAME-change names of files.
DISKIT- copies disks.
PIP-copy files back and forth between disks, the screen, serial and parallel ports.
Copyright © 2003, Dr. Ken Hoganson
CP/M File types
CS 8422 Advanced Computing Systems, Dr. Hoganson
File type
ASM
PRN
HEX
BAS
INT
COM
PLI
REL
TEX
BAK
SYM
$$$
Meaning
Assembler
Source
Printer Listing
Hex Machine
Code
Basic Source
File
Intermediate
Code
Command File
PL/I Source File
Relocatable
Module
Copyright © 2003, Dr. Ken Hoganson
•
CP/M
implements a
named file
structure on
each disk,
providing a
logical
organization
that allows any
particular file to
contain any
number of
records from
completely
empty to the full
capacity of the
drive.
CS 8422 Advanced Computing Systems, Dr. Hoganson
The Origins of MS-DOS
Sui-Tung Ng
CS 8422, Spring 2003
Advanced Computing Systems
Copyright © 2003, Dr. Ken Hoganson
Tim Paterson
CS 8422 Advanced Computing Systems, Dr. Hoganson
• Tim Paterson
- Original author of MS-DOS
- graduated from U of Washington in 1978
- worked as an engineer in Seattle Computer
Products
- designed an 8086 CPU card for S-100 Bus in May
1979
- began designing DOS in 1980 after IBM had
released
their new 8086 microprocessor (16-bit)
• objectives in design of DOS
- as simple as possible
- make it fast and efficient
- written
in 8086
language
• In
college, Paterson
wroteassembly
a multi-tasking
operating system for the Z80
microprocessor as a term project. Therefore, Paterson had confidence in
writing an OS for 8086 computer. Patterson spent half of his time working on
Qdos from April to July, 1980. QDOS was completed in July, 1980.
Copyright © 2003, Dr. Ken Hoganson
Tim Paterson
CS 8422 Advanced Computing Systems, Dr. Hoganson
• took two man-months to create Quick and
Dirty Operating System (QDOS)
• used Microsoft Stand-Alone Disk BASIC to
handle file organization
• was hired in Microsoft in 1981
• in and out of Microsoft in 1980s
• joined Microsoft again in 1990
•
QDOS could work with Microsoft Stand-Alone Disk BASIC that used a File
Allocation Table (FAT).
Copyright © 2003, Dr. Ken Hoganson
Seattle Computer Products
CS 8422 Advanced Computing Systems, Dr. Hoganson
• located in Tukwila of Washington
• manugacturer of S-100 memory cards
• a hardware company, not software company,
in 1980
• worked with Microsoft and Digital Research
• shipped its first 8086 cards with Microsoft
Stand-Alone Disk BASIC in Nov 1979
• gave up to use Digital Research CP/M-86 as
its operating system in 1980
• decided to create its own DOS
•
Seattle Computer Products (SCP) gave up to use CP/M-86 as Digital Research
could not promise when it would be completed. Finally, SCP decided to develop
its own DOS.
Copyright © 2003, Dr. Ken Hoganson
Seattle Computer Products
CS 8422 Advanced Computing Systems, Dr. Hoganson
• QDOS - completed in July 1980
• QDOS 0.10 - launched in Aug 1980
• 86-DOS version 0.3 - released at the end of
1980
• sold non-exclusive rights to Microsoft to
market 86-DOS
• released 86-DOS version 1.00 in Apr 1981
• similar to the MS-DOS of today
•
Seattle Computer Products (SCP)was a hardware company, therefore it was
willing to sell the non-exclusive right for Microsoft to market its 86-DOS at that
time.
Copyright © 2003, Dr. Ken Hoganson
Microsoft
CS 8422 Advanced Computing Systems, Dr. Hoganson
• paid SCP $10,000 for the right to market 86DOS and
• paid SCP $15,000 for each OEM customer in
1981
• got a secret customer for DOS - IBM
• bought DOS from Seattle Computer by paying
$50,000
• plus a license to include DOS in their PCs in
July 1981
• named DOS as MS-DOS
Microsoft had been
working with IBM as
on their
computer
project and
•• provided
86-DOS1.14
OSpersonal
in IBM’s
PCs
advised IBM to Digital Research for the operating system. However Digital
• released
MS-DOS
versionagreement.
1.24 to
IBM
Research refused
to sign a non-disclosure
Finally,
Microsoft offered
with DOS by buying the rights to market DOS from SCP.
• IBM
released
MS-DOS version 1.25 to the public
in Mar 1982
Copyright © 2003, Dr. Ken Hoganson
Microsoft
CS 8422 Advanced Computing Systems, Dr. Hoganson
• released MS-DOS version 2.0 to IBM new XT
computer in Feb 1983
• settled the license dispute by buying the
license back from SCP for $975,000 in 1986
• the total price for DOS ended up $1,050,000
• launched MS-DOS to its OEM in 1982
• kept improving and evolving DOS for 15
years
• stopped updating DOS until Windows95 was
released in 1995
•
Microsoft kept improving and evolving DOS after buying the products
completely from SCP. MS-DOS became a very popular Operating System in the
PC markets.
Copyright © 2003, Dr. Ken Hoganson
MS-DOS Timeline
CS 8422 Advanced Computing Systems, Dr. Hoganson
•
•
•
•
•
•
•
•
•
•
Year
12/1980
07/1981
09/1982
03/1983
11/1983
12/1983
09/1984
11/1984
04/1986
DOS Version
QDOS
86-DOS
MS-DOS 1.25
MS-DOS 2.0
MS-DOS 2.01
MS-DOS 2.11
MS-DOS 3.0
MS-DOS 3.1
MS-DOS 3.2
Copyright © 2003, Dr. Ken Hoganson
MS-DOS Timeline
CS 8422 Advanced Computing Systems, Dr. Hoganson
•
•
•
•
•
•
•
•
•
•
04/1987
04/1988
07/1988
11/1988
04/1989
04/1991
03/1993
11/1993
04/1994
08/1995
MS-DOS 3.3
MS-DOS 3.31
MS-DOS 4.0
MS-DOS 4.01
MS-DOS 4.01a
MS-DOS 5.0
MS-DOS 6.0
MS-DOS 6.2
MS-DOS 6.22
MS-DOS 7.0
•
Above timeline shows that Microsoft spent time to develop and market the MSDOS from 1980 to 1995. The development cost of MS-DOS was high over the
past 15 years.
Copyright © 2003, Dr. Ken Hoganson
Conclusion
CS 8422 Advanced Computing Systems, Dr. Hoganson
• Tim Paterson was the original author in DOS
• MS-DOS was an easy-to-use operating system
• Microsoft successfully launched MS-DOS to
IBM and to the PC market
• Microsoft kept improving and evolving the MSDOS over the past years
• Microsoft integrated MS-DOS with its windows
operating system in 1995
•
Without the efforts of Microsoft, DOS will not be the popular operating system
in 1980s and 1990s. MS-DOS now is integrated in Windows 95, 98, NT, and
2000.
Copyright © 2003, Dr. Ken Hoganson
CS 8422 Advanced Computing Systems, Dr. Hoganson
References
• A short history of MS-DOS. (2003). Retrieved February
21, 2003, from
http://www.patersontech.com/Dos/Byte/History.ht
ml.
• Conner, D. (1998). Father of DOS still having fun at
Microsoft. Retrieved February 21, 2003, from
http://www.patersontech.com/Dos/Micronews/pater
son04_10_98.htm.
• DOS timeline. (2003). Retrieved February 21, 2003,
from
http://www.powerload.fsnet.co.uk/timeline.htm.
• Hunter, D. (2003). Retrieved February 21, 2003, from
http://www.patersontech.com/Dos/Softalk/Softalk.h
tml.
Copyright © 2003, Dr. Ken Hoganson
CS 8422 Advanced Computing Systems, Dr. Hoganson
References
• MS-DOS review. (2003). Retrieved February
21, 2003, from
http://www.michaelh.com/comp/msdos.sht
ml.
• Paterson, T. (2003). DOS. Retrieved February
21, 2003, from
http://www.patersontech.com/Dos/Encyclo.
htm.
• The Dross of the DOS. (1997). Retrieved
February 21, 2003, from
http://www.forbes.com/asap/1997/1201/07
0_print.html.
Copyright © 2003, Dr. Ken Hoganson
CS 8422 Advanced Computing Systems, Dr. Hoganson
History of VAX/VMS – Quality by Design
Jerry Samples
CS 8422, Spring 2003
(photo from “VAX OpenVMS at 20”, Digital Equipment Corp., 1997)
Copyright © 2003, Dr. Ken Hoganson
Overview
CS 8422 Advanced Computing Systems, Dr. Hoganson
• VAX and VMS were products of Digital
Equipment Corporation (DEC was acquired by
Compaq in 1998)
• VAX refers to the hardware architecture
• VMS operating system co-designed with VAX
hardware
• Digital
First
VAX/VMS
computer
was
VAX
11/780,
Equipment
Corporation (DEC)
was founded in
1957 and
produced
the very
successful PDP family of minicomputers. However, for different markets, DEC had created
different,
andout
incompatible,
operating 1977.
systems for the PDP hardware. In the mid-1970’s,
rolled
October
DEC began work to develop a family of computers that would be priced over a wide range,
•
from very affordable workstations, up to mainframe-class, but which would all be softwarecompatible and have a consistent user interface.
Copyright © 2003, Dr. Ken Hoganson
Naming
CS 8422 Advanced Computing Systems, Dr. Hoganson
• VAX is acronym for Virtual Address eXtension
• VMS stands for Virtual Memory System
• “11” in VAX 11/780 indicates compatibility
with PDP-11, DEC’s previous-generation
workhorse minicomputer
•
One of the driving forces in the creation of VAX and VMS was the recognition that 16-bit
addressing, which dominated all computing until the mid-1970’s, was limiting program size
and complexity. VAX/VMS was designed to extend the 16-bit addressing of PDP computers
to 32-bits. Also, main memories generally were not very large, ranging from 10’s of
kilobytes up to perhaps 4 megabytes. With VMS’s virtual memory techniques, very large
programs could be created and managed transparently, rather than forcing programmers to
break their code into a number of separate, small programs.
Copyright © 2003, Dr. Ken Hoganson
Design Goals – A Tall Order
CS 8422 Advanced Computing Systems, Dr. Hoganson
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•
•
•
•
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•
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Multi-user
High-performance
32-bit addressing
High reliability
15 – 20 year architecture life span
“Culturally compatible” with PDP-11 (look and feel)
Compatible with PDP-11 software
Quick to market
Multiprocessing
Network support and distributed computing
Excellent documentation
The vision of DEC cofounder Ken Olsen was affordable computers for the masses. Once the
success of the VAX project was assured, DEC adopted a strategy of “one platform, one
operating system, one network” and focused most effort on the VAX/VMS family. In
designing VAX and VMS, hardware and software teams worked closely, each influencing the
other, to achieve an outstanding final product. It is generally acknowledged that all the
design goals were fully met, with first product shipping only 31 months after project start.
Copyright © 2003, Dr. Ken Hoganson
VAX on a chip
CS 8422 Advanced Computing Systems, Dr. Hoganson
• 1977 - first VAX architecture, 11/780, based
on existing PDP technology (boards, bus, I/O,
etc.)
• 1980 – VAX 11/750 uses LSI ICs to shrink
size, boost performance
• 1985 – MicroVAX chip implements subset of
VAX architecture on a single microprocessor
• 1986 – V-11 chip implements complete VAX
architec-ture;
usedbetween
in mid-range
VAX
8200
•
DEC
always struck a healthy balance
hardware and software.
VAX and
VMS were
co-designed from the beginning. As electronics technology advanced, the architecture was
and 8300 models
ported again and again to smaller and faster hardware implementations, but never losing
VMS compatibility. Eventually, DEC products ranged from under $5000 for a VAXstation
2000, up to $5.2M for the top-of-the-line VAX 8978.
Copyright © 2003, Dr. Ken Hoganson
Dave Cutler
CS 8422 Advanced Computing Systems, Dr. Hoganson
• Dave Cutler was one of VAX/VMS chief
architects, later went to Microsoft and led
development of Windows NT
•
Dave Cutler, outlined by the red oval, was one of three chief software engineers who, along
with three hard-ware engineers, originally designed the VAX/VMS system. He also led the
design effort for DEC’s 64-bit RISC chip, Alpha. Dave Cutler later went to work for
Microsoft, leading development of Windows NT. Many of NT’s features, such as the virtual
memory manager, were descendents of VAX/VMS technologies.
•
(photo from “VAX OpenVMS at 20” by Digital Equipment Corporation, 1997)
Copyright © 2003, Dr. Ken Hoganson
VMS Virtual Memory
CS 8422 Advanced Computing Systems, Dr. Hoganson
• Paging – moving portions of memory for a
process from physical (main) memory to a
disk file (“page file”)
• Swapping – moving all memory related to a
process from physical memory to a disk file
(“swap file”)
• Two-level paging system
improved
performance
of asize
process currently in the queue for scheduling, paging is
• For
512
byte
page
performed. A process will generally be allocated less physical (main) memory than it
•
logically requires. VMS automatically moves the necessary 512-byte pages between
physical memory and the process’s page file. Each process has its own page file. There is
also a swap file for the entire system. When a process is to be taken off the scheduling list,
all of the memory related to the process is placed in the swap file.
Copyright © 2003, Dr. Ken Hoganson
Digital Command Language
CS 8422 Advanced Computing Systems, Dr. Hoganson
• Digital Command Language (DCL) is the
command-shell language of VMS
• Provides dozens of commands with Englishlike names, not cryptic mnemonics, as in Unix.
• Most commands support numerous qualifiers
• May be grouped inside command files (.COM)
for automated execution
•
Digital Command Language (DCL) is the shell language of VMS, similar to MS DOS’s
command line or Unix shells, such as the Korn or Bourne shells. Most DCL commands, and
there are dozens, can be executed from a command prompt (a dollar-sign by default).
Command files, similar to shell scripts or batch files, are also supported. These are invoked
by giving the command file’s name prefixed with the “@” sign.
Copyright © 2003, Dr. Ken Hoganson
Common DCL Commands
CS 8422 Advanced Computing Systems, Dr. Hoganson
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The DCL commands may be fully spelled out for clarity, but they may also be abbreviated to
as few characters as will uniquely identify the command. The types of functions that can
be performed with DCL are similar to Unix or DOS. These include file and directory creation
and management; input and output, including magnetic tapes, printers, terminals,
keyboards, etc.; and obtaining various kinds of system and user status information.
(table taken from OpenVMS Documentation website:
http://www.openvms.compaq.com/doc/ )
Copyright © 2003, Dr. Ken Hoganson
Example DCL Usage (1)
CS 8422 Advanced Computing Systems, Dr. Hoganson
• Creation of .COM file, followed by execution
•
The figure illustrates creation of a DCL command file, named DOFOR.COM. It is opened for
writing by the CREATE command, then each of the next six lines are added literally to the
file. [Ctrl/Z] represents a keyboard command which closes the file. The final command,
@DOFOR AVERAGE, executes the command file and passes it the argument AVERAGE.
(cont’d)
•
(figure taken from OpenVMS Documentation website:
http://www.openvms.compaq.com/doc/ )
Copyright © 2003, Dr. Ken Hoganson
Example DCL Usage (2)
CS 8422 Advanced Computing Systems, Dr. Hoganson
• Creation of .COM file, followed by execution
•
(cont’d) The argument is represented inside the command file by the replaceable
parameter, P1. When executed, DOFOR.COM calls a FORTRAN compiler, then links and runs
the program. Finally, it prints the listing file (.LIS). Note that, if no source file name is
provided as an argument, the user is prompted (INQUIRE) for a file name. Command files
may be nested (i.e. may call other command files) by using the “@” sign within the
command file. Comments in a command file are indicated by lines beginning with “$!”.
Copyright © 2003, Dr. Ken Hoganson
DECnet networking
CS 8422 Advanced Computing Systems, Dr. Hoganson
• DEC pioneered peer-to-peer networking in
early 1970’s with DECnet technology
• DECnet was DEC’s solution for distributed
computing
• DECnet peer-to-peer more flexible than IBM’s
hierarchical solutions of the time
• DECnet originated as point-to-point, then
•
Even
before creationto
of the
VAX/VMSarea
family, DEC
recognized the need
to interconnect
extended
local
networks
and
OSI and
multiple computers and peripheral resources. Its early research connected multiple
minicomputers
effectively achieve a multi-processor system with mainframe-class
TCP/IP tostandards
performance. The interconnect technology was introduced under the name DECnet in
1974. The first VAX/VMS systems (1977) included DECnet support. DECnet offered several
size/performance options, from high-performance, room-sized clustering, to 1.5 mile radius
Ethernet LANs.
Copyright © 2003, Dr. Ken Hoganson
Clusters
CS 8422 Advanced Computing Systems, Dr. Hoganson
• Clustering concept originated by DEC,
introduced 1983
• Cluster is a highly-cooperative network of
separate computers, acting as single system
• Clustering effectively creates a multiprocessor
system
• Older and newer systems can be clustered to
leverage all existing investments
•
Clustering was DEC’s very elegant solution to a number of issues. Working together,
clustered DEC mini-computers could provide performance equivalent to mainframe
computers at a fraction of the cost. Clusters also provided high-availability because of the
multiple processors, which users only perceived as a single system. Finally, DEC clusters
allowed almost any VAX family computer to be clustered with others, from older, large or
small VAX computers, to newer Alpha-based (see next slide) systems.
• Clusters offer high-availability
Copyright © 2003, Dr. Ken Hoganson
Alpha 64-bit RISC
CS 8422 Advanced Computing Systems, Dr. Hoganson
• In 1992, DEC released the Alpha RISC
processor, the world’s first 64-bit architecture.
• Three industrial-strength operating systems
(VMS, Unix, and Windows NT) were ported to
run on Alpha
• Alpha AXP became the family name for a wide
range of product offerings
•
Never ones to rest on their past or current successes, in the late 1980’s, DEC pursued the
goal of creating a new leading edge processor. They developed a RISC processor, which
was also the world’s first 64-bit architecture. Known as Alpha, the processor was used in
the Alpha AXP family of products, which ranged from workstations to mainframe-class
machines. Alpha systems are network-compatible with VAX systems, although the
instruction set architecture is totally different (RISC vs. CISC).
Copyright © 2003, Dr. Ken Hoganson
OpenVMS
CS 8422 Advanced Computing Systems, Dr. Hoganson
• Around 1993, VMS was renamed OpenVMS
• OpenVMS supports the IEEE POSIX standard
• Also supports OSF/Motif, OSF/DCE, XGP4 and
other interoperability standards
•
DEC always empowered its users in many ways. Via DECnet, VAX computers could
interoperate with computers from other providers. DECnet also quickly evolved to support
Ethernet, OSI, and TCP/IP networking standards. So it is not surprising that they also
adopted support for operating system and software standards, such as IEEE’s POSIX
(standard operating system API), OSF/Motif (standard GUI specification), etc. OpenVMS is
really the same as VMS, with some possible enhancements for standards support.
Copyright © 2003, Dr. Ken Hoganson
User groups and enthusiasts
CS 8422 Advanced Computing Systems, Dr. Hoganson
• DEC products have tremendous user loyalty, especially
PDP, VAX and VMS systems
• Many enthusiast user groups and websites exist
• Much information and documentation available on
Web
• Systems still readily available for collectors and
hobbyists
• Open source and shareware software available
•
From the beginning, DEC products inspired great user loyalty due to their high quality, flexibility, and
designs that matched their users’ needs. In addition, DEC’s attention to business factors, such as
compatibility of product family members, scalability, and long product life spans, earned the respect of
business, as well as technical, customers. To this day, many enthusiast groups exist and many people
collect older DEC systems and share open-source software.
Copyright © 2003, Dr. Ken Hoganson
Bibliography
CS 8422 Advanced Computing Systems, Dr. Hoganson
• Digital Equipment Corporation (1997). VAX
OpenVMS at 20. (available at:
http://www.openvms.compaq.com/openvms/
20th/
• http://www.openvms.compaq.com/doc/
• Abraham Silberschatz, P. Galvin, G. Gagne.
(2003). Operating Systems Concepts, 6th
edition. New York: John Wiley and Sons.
•
My primary source of information for this presentation was “VAX OpenVMS at 20”, a 66page retrospective document of the history and development of the VAX and VMS products.
It was published in 1997 on the 20th anniversary of release of the first VAX, the 11/780.
Less than a year later, DEC was acquired by Compaq Computer. A PDF version of this
document is available from the Compaq OpenVMS website, which also contains a large
amount of OpenVMS user documentation.
• http://www.utexas.edu/cc/docs/ccug2/
Copyright © 2003, Dr. Ken Hoganson
End of Lecture
CS 8422 Advanced Computing Systems, Dr. Hoganson
End
Of
Today’s
Lecture.
Copyright © 2003, Dr. Ken Hoganson