In 1981 when the original IBM Personal
Computer was announced, IBM released three operating systems
for it. How many of you remember that? Since I wrote the
first IBM course on how to fix this original PC, I had to
know at least a little about all three of them.
IBM decided early in the development process
of the PC that they did not want to hire a bunch of
programmers to write software for it - especially an
operating system. IBM wanted the hardware business and did
not care about the software. Since there was no clear-cut
contender for an operating system at the time, IBM
approached three organizations about writing one for the PC.
IBM first approached Digital Research and
asked them to create a version of CP/M (Control
Program/Microcomputer). The owner of DR snubbed the IBM
lawyers and went flying or golfing (depending upon whose
story you hear) instead.
IBM then turned to Microsoft. Bill Gates was
very receptive to the IBM overture and also had information
about an operating system which had already been written
that would fill IBM's need very nicely. Gates said yes to
IBM, bought the operating system called DOS for $20,000 and
modified it somewhat to run on the IBM PC.
For you trivia buffs, the other OS delivered
with the original PC was the UCSB P-System (University of
Southern California at Berkely Pseudo code System). I will
permit those who make a living from documenting the history
of computers to describe that operating system elsewhere.
I suppose we all know what assumptions can
do for us. IBM made some interesting assumptions about the
original PC in 1981; or rather, Don Estridge and his very
autonomous development team did.
I was in a meeting with Estridge and a
number of other people in April of 1981, when I first was
assigned to write the IBM education for the PC. It was
stated at this meeting that IBM expected to sell about
275,000 Personal Computers - over a five year product life.
in fact, IBM sold almost that many on August 11, the day
before the official announcement. IBM held a preannouncement
showing of the PC in Toronto at the annual ComputerLand
Dealers of North America conference. ComputerLand dealers
placed orders for nearly 250,000 computers that day. On
August 12, IBM took orders for almost 250,000 more Personal
Computers. IBM's planners have not been correct since.
At the same meeting the target environment
for the PC was described. Here are some of the assumptions
Small business would buy most PCs.
Large business would stick with mainframes and dumb
A few departments in large businesses would use PCs for
local, non-connected work.
The PC would be used for one task only. Not just one task at
a time, but a single task all day long. This might be a
spreadsheet, or word processing, or accounting, but no more
than one task would be performed all day.
Based on these assumptions, the operating
system was specified to be single tasking. Besides, although
the hardware was far more powerful than anything else
available in the microcomputer market at the time, it just
was not powerful enough to warrant the extra load that
multitasking would place on it.
As we all know, DOS became the OS of choice
for the Personal Computer. In part, this was due to its
significantly lower price when compared to the other
operating system choices then available for the PC.
As soon as I bought my original PC ($5,000
for Intel 8088, 4.77 MHz, 96 KB RAM, monochrome display
adapter and display, 80 CPS dot matrix printer) I ran into
I was writing a letter in EasyWriter and
needed to make a calculation so I could use the result in
the letter. Why should I get out a $10 calculator when I
have a $5000 one sitting here? Of course in order to use it
as a calculator, I have to save my document, close
EasyWriter, reboot to another diskette with the calculator
program on it (which I wrote myself in BASIC), do the
calculation, write down the answer, reboot to the diskette
with EasyWriter, load the document, and type in the figure
from the paper.
We needed multitasking already.
A couple smart companies like Borland came
out with Terminate and Stay Resident (TSR) programs like
Sidekick which allowed you to switch to them by pressing a
special key combination. Sidekick had the calculator as well
as a calendar, notepad, schedule, and other little utilities
which we all needed.
The TSR became a circumvention for the lack
of intrinsic multitasking in DOS and the PC.
The PC AT - 1984
In 1984, IBM introduced the PC-AT which was
the first (IBM) PC to use the new Intel 80286 processor. The
80286 was designed by Intel with support for multitasking
built into it. IBM made a promise to its customers that they
would provide a multitasking operating system for the PC-AT.
IBM keeps its promises, unlike Microsoft.
The PC-AT was supposed to be able to do
multitasking, and some IBM publicity photos even showed it
connected to two dumb terminals. IBM had contracted
Microsoft to create the first multitasking OS for the PC,
but Bill Gates really did not want to do this for the 80286
processor. He publicly called the 80286 "brain dead" and
constantly attempted to turn IBM away from creating OS/2 for
the 80286 and to jump instead to the 80386 which was then
under development at Intel.
Most people don't know this, even many
IBMers who should, but IBM has a series of internal
documents called Corporate Directives. Corporate Directive
number 2, signed by Thomas J. Watson Jr. in 1956, states
that when IBM makes a promise to its customers it will keep
that promise "...regardless of the cost." It was on this
basis that IBM pressured Microsoft to continue work on OS/2
At this time, the IBM PC was the
responsibility of Entry Systems Division (ESD). ESD was also
working closely with Microsoft to produce OS/2. During this
time, Microsoft was also working on the first versions of
Windows, and IBM was working on a product called TopView
which was a DOS add-on that allowed text mode multitasking.
Most people do not remember TopView, but it was a good
product and I used it between 1984 and 1987 when OS/2 1.00
OS/2 1.00 - 1987
Released in December, 1987, OS/2 1.00 was
the first ever operating system for the Personal Computer to
provide intrinsic multitasking based on hardware support. It
was text mode only and allowed only one program to be on the
screen at a time, even though other programs could be
running in the background. It also allowed one very limited
session in which DOS programs could be run. The maximum disk
size supported was 32 MB.
Note: All 1.x versions of OS/2 were designed
specifically to run on 80286 systems, but they were capable
of running on 80386 systems as well.
OS/2 1.10 SE - 1988
In October, 1988, IBM released OS/2 1.10
Standard Edition (SE). SE 1.10 added a graphical user
interface (GUI) to OS/2. This GUI, called Presentation
Manager (PM), allowed users to interact with the operating
system in a more friendly manner than the command line
Unfortunately the PM required a very large
learning curve on the part of programmers. When programmers
became proficient they found that PM, and the rest of the
OS/2 APIs (Application Programming Interfaces), were very
powerful and quite efficient.
Support for large FAT hard drives was
included in this version. By dividing large physical drives
into multiple logical hard drives, up to 2 GB drives could
OS/2 1.10 EE - 1989
When IBM announced OS/2 1.10 SE, they also
announced OS/2 1.20 EE (Extended Edition). This product,
released in early 1989 included Database Manager and
Database Manager was (and is) a multitasking
relational database with a great deal of power.
Communications Manager provided IBM
mainframe and midrange customers with multiple 3270 and 5250
emulation sessions. It also contained a really bad
asynchronous communications program.
OS/2 1.20 - 1989
Released in November 1989, OS/2 1.20 (SE and
EE) offered an improved Presentation Manager. Available with
OS/2 1.2 EE for the first time was the High Performance File
System (HPFS). HPFS is much more efficient and faster than
FAT. HPFS also offers much greater data integrity.
REXX also appeared for the first time in
OS/2 1.20 Extended Edition. REXX is a very powerful
interpretive programming language which can be used for
writing a complete application or as an extended batch
language. I use REXX quite frequently to write everything
from quick and dirty programs to do something one time, to
very large, sophisticated programs which I use constantly.
Work had also begun on two new OS/2
products. Work on OS/2 2.0 was well underway. This product
would be the first true 32 bit operating system for personal
computers. Designed to work on the Intel 80386 and its
follow on processors which were still in development, OS/2
2.00 would no longer be compatible with the 80286 processor.
OS/2 3.0 was in the very early stages of
development and was intended at the time to be a network
server version of the operating system. It was also intended
to be platform independent. Because the operating system
would be built on top of a microkernel, it would not need to
be aware of the type of hardware on which it was running and
therefore could run on Intel processors as well as Motorola,
SUN, and DEC, chips with only a change of the microkernel
hardware abstraction layer.
1990 - The Schism
In 1990, IBM and Microsoft were still
working together on the development of OS/2. Microsoft,
however, had found that Windows 3.0 - released in May 1990 -
generated more revenue for them and therefore allotted
increasingly more resource to Windows and correspondingly
less to OS/2.
By late 1990, Microsoft had intensified its
disagreements with IBM to the point where IBM decided that
it would have to take some overt action to ensure that OS/2
development continued at a reasonable pace. IBM, therefore,
took over complete development responsibility for OS/2 1.x,
even though it was in its dying days, and OS/2 2.00.
Microsoft would continue development on Windows and OS/2
3.00. Shortly after this split, Microsoft renamed OS/2 V3 to
OS/2 1.30 - 1991
OS/2 1.30 (SE and EE) was the first version
which was written entirely by IBM. There was still some
Microsoft code in it - that would not go away for a couple
years yet - but all of the new code and a good portion of
the existing code for OS/2 1.30 was written by IBM. As a
result, OS/2 1.30 was smaller and faster than previous
versions, more stable, and there were far more device
drivers available, though still not nearly enough.
It has never ceased to amaze me that
Microsoft could write code for Windows which was (relative
to OS/2 1.1 and 1.2) easy to use and for which there were
plenty of device drivers. Take the process required to
install and configure a printer. Under Windows it was a
simple two step process. Under OS/2 1.2 it required the user
to perform unnatural acts:
Install the device drivers.
Set up a printer queue.
Create a printer object.
Associate the device driver with the printer object.
Associate the print queue with the printer object.
Set up the COM port configuration for a serial printer.
Use the SPOOL command to redirect printer output to the
Specify optional printer settings.
No wonder people thought OS/2 was difficult!
In my opinion, Microsoft was intentionally making OS/2 as
difficult to use as possible - or the programmers they had
assigned to write OS/2 were the stupid ones. I still have a
copy of the three page article I wrote for what was then
OS/2 and Windows Magazine (it later became Windows magazine
and never had any relationship to the late, lamented OS/2
Magazine) describing in detail the steps required to install
and configure a printer under OS/2 1.20.
With IBM writing OS/2 1.30, the printer
installation became much easier, as did much of the
installation and configuration. IBM completely rewrote the
Print Manager in order to achieve this. It was not great
yet, but it was incomparably better than it had been.
OS/2 1.30 added some other important new or
REXX was added to the SE version. It had
previously only been available with EE.
Adobe Type I type fonts. (It was shortly after this that
Microsoft began development of TrueType fonts. Interesting!)
New, more easily readable fonts for the command prompt
Lazy Write was added to the HPFS file system.
The swapping algorithm was improved considerably to enhance
Video device drivers were enhanced to include high
resolutions up to 1024x768.
OS/2 2.00 - 1992
OS/2 2.00 was released in the spring of
1992. The first true 32 bit operating system for personal
computers (and for years the only one), it met IBM's stated
goal of being a better DOS than DOS and a better Windows
than Windows. It did this through the use of Virtual DOS
Machines (VDMs) which allowed OS/2 to run many DOS (and
Windows) programs at the same time as though they were on
completely separate computers. As far as the DOS programs
were concerned, they actually were in separate computers.
Windows programs run on IBM's licensed version of Windows
3.1 called Win-OS/2.
Because of this separation of DOS programs
from each other, one Windows (remember - Windows is a DOS
program) program which crashes can not crash any other
Windows program. By placing Windows programs which do not
play well together in Windows sessions in different VDMs,
they can both run without interfering with each other. In
addition the programs can still communicate through Dynamic
Data Exchange and the clipboard.
The Workplace Shell (WPS) was also
introduced in OS/2 2.00. The Workplace Shell is an object
oriented user interface (OOUI). The IBM WPS takes the GUI to
the next generation by integrating it much more fully with
the rest of the operating system, including the file system.
OS/2 2.10 - 1993
In May of 1993, IBM released OS/2 2.10. This
version sported a new, faster, fully 32 bit graphics
subsystem, TrueType fonts for Win-OS/2 sessions, and
Multimedia Presentation Manager (MMPM/2) which provided
sound and video multimedia capabilities.
PCMCIA support for laptop computers also
made its debut with OS/2 2.10, along with Advanced Power
Management (APM). OS/2 could work with laptop computers with
an APM BIOS to reduce power consumption and extend battery
life. PCMCIA support was crude and supported only a very few
computers and PCMCIA credit card adapters.
To reduce the price of OS/2 for users who
already had Windows on their computers, IBM released OS/2
2.11 for Windows in late 1993. This version of OS/2 did not
have Win-OS/2 and, instead, relied upon the copy of Windows
3.1 already installed on the computer to allow OS/2 to run
Windows programs. It did this by making some minor
modifications to the Windows SYSTEM.INI and WIN.INI files,
and hooking the Windows 3.1 code once it was loaded into
memory so that OS/2 could control the Windows 3.1 code in
OS/2 Warp - 1994
OS/2 Warp Version 3 made its debut in
October 1994 as OS/2 Warp for Windows. Like OS/2 2.11 for
Windows, it did not contain IBM's Win-OS/2 code and relied
on Windows 3.1 to run Windows programs. OS/2 Warp 3 with
full Win-OS/2 support became available a short time later.
Warp 3 was designed to install and run on a
computer with only 4MB of RAM and it did. Performance was
tolerable, but adding more RAM improved performance
considerably. Additional device drivers made Warp 3 capable
of running with the vast majority of personal computers and
peripherals on the market. The Workplace Shell was improved
significantly in terms of both its functionality and
performance. Print performance, PCMCIA support, and
multimedia support were all enhanced significantly.
TCP/IP and Internet communications were also
added to Warp 3. The Internet Access Kit (IAK) provided a
complete package to enable Warp users to log on and surf the
net. The Web Explorer allowed users access to the World Wide
Web, although it was neither as feature rich nor as flexible
as the industry leader, NetScape. Text mode and graphical
FTP applications allowed file transfer. Ultimail Lite gave
users e-mail, but Ultimail is cumbersome, slow, and very
difficult to configure.
Unlike previous versions of OS/2, Warp
shipped with a BonusPak CD-ROM which contained several OS/2
applications. IBM Works is a set of integrated applications
including a spreadsheet, word processor, database, report
generator, and charting program.
Released in 1995, Warp Connect combines all
of the features of Warp 3 with network connectivity and
tools. Warp Connect Peer functions allow client workstations
to share resources such as files, printers, and modems with
other users on a network. LAN Server 4.0 and Netware
requesters allow access to the most popular network server
In early 1996 IBM released Warp Server. This
landmark product combines the power and functionality of
Warp 3 with the network server capabilities of IBM's LAN
Server 4.0 product. With some relatively minor fixes to the
LAN Server product, and the addition of many previously
separate products, Warp Server is the leading server
Warp Server includes many features which
would cost extra with other server operating systems. OS/2
Warp Server delivers an integrated platform for the emerging
application server environment as well as a complete set of
traditional file and print services. Warp Server provides an
integrated packaging of OS/2 Warp, LAN Server 4.0 (with some
enhancements and fixes), SystemView for OS/2, remote access,
advanced backup disaster and recovery, and a new printing
capability that allows, among other things, printing
postscript files on non-postscript printers.
OS/2 Warp 4 - 1996
Warp 4, code named Merlin, was released in
September of 1996 with a significant facelift for the
Workplace Shell. New features include Java, and VoiceType
Navigation and Dictation.
Warp 4 is called the "Universal Client" by
IBM because of its unparalleled network connectivity.
Connect to anything, anywhere with a
universal network client which allows simultaneous
connectivity to LAN Server, Warp Server, Windows NT Server,
Novell Netware, Netware Directory Services, PCLAN Program,
IPX-SPX, LANtastic for DOS or OS/2, Warp Connect, Windows NT
Workstation, Windows 95, Windows for Workgroups, TCP/IP
(including DHCP, DDNS, FTP, TFTP, Telnet, SLIP, PPP, SMTP,
and SNMP), SNA, NetBIOS. Java is built into Warp 4 so you
need no additional software to run powerful and easy Java
applications locally or right from the World Wide Web.
VoiceType speech recognition makes Warp 4 the only operating
system in the world to allow voice navigation and dictation
with no additional software.
WarpGuides provide intelligent self-configurable guidance
for common tasks. Ideal for new users or users new to OS/2.
Internet aware desktop allows one-click access to your
favorite web sites.
TME 10 Netfinity (SystemView) for exceptional systems
management, including DMI (Desktop Management Interface)
Remote Access Services (LAN Distance) for remote access
capabilities which allow you to access your network from
home or the road. Remote Access Services can also allow
adhoc WAN configuration for temporary or emergency use.
Mobile Office Services allows the Road Warrior to keep files
synchronized with the office.
David P. Both is president and founder of
Millennium Technology, Inc., a computer consulting firm in
Raleigh, North Carolina which specializes in OS/2 Warp, OS/2
Warp Server and related products, and Lotus Notes. He spent
the last eight of his 21 years with IBM as the lead support
person for OS/2. He is co-author of the book Inside OS/2
Warp, New Riders Publishing, 1995, and has published
articles in Windows and OS/2 Magazine, Carolina Computer
News, LAN Magazine, OS/2 Magazine, and others. He holds nine
IBM technical certifications and is a Premier IBM Business
When Tim Paterson became the "father
of DOS" at the age of 24 it should not have come as a great shock to anyone
who knew him well. Growing up with a father who was an electrical engineer says
Paterson, "I got a lot of exposure to electronics stuff at home." He also says
that he learned a lot by reading and simply by experimenting on his own. It was
not until he went off to the University of Washington, however, that he first
came into contact with PC's. His roommate bought one and let him play around
with it. At the same time, Paterson was working as a technician at a retail
computer store in the Seattle area. This position allowed him to begin trying
to design his own computer boards. more...