section 1
History of OS/2 and eCS
Once upon a time we had DOS
It was a time when IBM primarily traded big and very big computers for vast amounts of money. It was a time when the craftmanship of nerds wasn't really taken seriously. IBM had noticed the potential of microcomputer chips, and produced these themselves. They even marketed the 5110 office microcomputer for a while bac in 1976, but even so were taken be surprise when around 1980 the personal computer energed.
Don Estridge, who was very unlike other IBM-crew at the time, was assigned to recope, and reestablish IBM's market dominance also is this new corner of the computer market. He created the Standard IBM PC with the DOS operating system, and doing so, got IBM onboard the new bandwagon just in time. By setting open standards for various interfaces, both hard- and software he established conditions by which a new industry could emerge and flourish.
The DOS operating system was picked in a hurry from a small unknown company called Microsoft, and was from the beginning defective and malfunctioning in many ways, but just good enough to compete with large corporate IT-departments who used to take years rather than month to fulfill promises about new system functions.
From that moment on three parallel developmenttracks took off, each of them as an approach to reduce the shortcomings of the DOS operating system. These shortcomings were centered around the well known 640 kB memory limit, around the lack of multitasking capability, but most of all around the lack of memory protection. Memory protection prevents applications access to memory segments in use by different programms, and thus prevents corruption of memory by programming errors or deliberate abuse of memory by other programs, which happens to be the most common cause of program failures.
These three development tracks were:
  1. Hardware solutions. One of the earliest hardware solutions came from IBM themselves. The PC 3270 was engineered to support three parallel banks of memory in the 128kB to 512kB address range. This allowed loading of three parallel programs, with a shared memory in the 0-128 kB and 512-640 kB ranges. Obviously one these programs was meant to be a 3270-terminal emulation program, which in combination with some video enhancements and an extended keyboard resulted in a full function 3270 terminal mode in parallel with two local PC applications. The PC 3270 was not very succesfull because of its price tag, which to a large extent was due to the availability of 1,5 MB of memory. Another limitation was that despite all the memory, still only 640 KB was accessable simultaneously, thus precluding its use by a single but more complicated and memory demanding application. This limitation was overcome by the LIM (Lotus Intel Microsoft) EMS (expanded memory specification) implementation, which emerged slightly later, and took much more followers.
  2. Software extensions to DOS. Do you remember Windows 1.0 which was released in 1986 ? Other software approaches from that time were Frameworks (Ashton Tate), Symphony (Lotus), Topview (IBM) and Sidekick (Borland), Desqview (Quarterdeck) and Taskmanager (Digital Research). The common denominator of these programs were the capability they offered to the user to handle multiple tasks in parallel. Each of them was succesfull to some degree, none of them lasted, due to the limitations in design or due to lack of marketing power, compared to Microsoft.
  3. Alternatives to DOS. Around 1984 IBM started the development of a new PC operating system. DOS was considered a stop gap solution to bridge the time between claiming marketshare and providing well crafted solutions. With the experience of DOS as well as the experience with large system operating systems, IBM felt it had the competence to create a new operating system for PC's which would eliminate all limitations and drawbacks of DOS, and which would unleashe the full competence of IBM on system design and development into the realm of personal computing.




December 1987 was the remarkable date when IBM launched a complete new range of PC's now called PS/2 (personal system), together with a new operating system OS/2. OS/2 version 1.0 was born. IBM was not overly lucky, and in hindsight may have made some marketing errors (misjudgements). OS/2 version 1.0 required a 80286 processor and a minimum of 2 MB of memory. However, most PC's in that timmeperiod were sold in the lower marketsegment, for which IBM introduced the lower cost PS/2 model 30, which had a 8086 processor and DOS ! So from the outset they diluted their marketing message concerning the OS/2 direction. OS/2 provided multitasking to OS/2 programs and had backward compatibilty for DOS programs by means of a DOs-box, which allowed a single DOS program in parallel to the OS/2 programs. OS/2 programs didn't exist initially and multiple DOS-boxes was precluded by a hardware limitation of the 80286 processor, in fact leaving the multitasking capability of OS/2 quite useless.
Meanwhile a competitive market of PC's had emerged, but most PC's didn't support OS/2, as OS/2 required multitasking compatible BIOS-calls. OS/2 therefore was initially limited to the upper market segment where only IBM and a few other A-brands of computers were sold.
A further limiation was the DOS-box itself. In OS/2 version 1.0 the DOS-box was designed to be compatible with DOS 3.3, and so copied all limiations of DOS 3.3. In particular it didn't support the LIM extensions, and therefore didn't support DOS applications which required LIM memory. In practice it meant that OS/2 only supported the older versions of popular applications. In particular one type of application that gradually enjoyed increasing popularity, and which was not supported in the DOS-box was the graphical shell type, like Windows, which at the time was advanced to version 2.1. However, IBM recognised the trend to graphical shells and announced a next version of OS/2, namely 1.1 which would include a Presentation Manager. This version was released November 1988.

Clearly OS/2, though it was fundamentally the right approach to solving the limitations of DOS, was not yet ready to compete with mainstream personal computing software developments. The next version of OS/2, version 1.2, which was released December 1989, didn't fundamentally change this, though it did bring some major improvements. Until version 1.2 OS/2 just used the DOS file system, FAT which suffered limitations in partitionsize (32 MB at the time) and was plagued by file fragemntation which severely impacted performance, a phenomenon aggravated by the multitasking usage enabled by OS/2. Version 1.2 introduced the high perfromance file system (HPFS), which eliminated many of the limitations of FAT, in particular, support for longer filenames than the DOS 8.3 format, support for large partitions and large files (up to 512 MB each, in later versions partition size was increased to 4 GB ) and resistance to file fragmentation.
Some of the other enhancements introduced with version 1.2 were: Dual boot, LAN requester, and REXX.

Then, early 1990, the cooperation between IBM and Microsoft was broken. May 1990, Microsoft released Windows 3.0 and IBM was forced to market to save the OS/2 development. On one side development was pushed to create a new 32-bit kernel which was based on the 80386 memory model, but while Windows 3.0 already exploited some of the 386 capabilities, an earlier signal to market was needed. So IBM launched OS/2 version 1.3, which was the first release without Microsoft co-operation. OS/2 version 1.3 was above all a performance release, with optimised coding relative to version 1.2. The most important new feature was the inclusion of the Adobe Type Manager, which brought the typographic support of the presentation manager alongside Windows 2.1 ! At last.

April 1992 finally marked the first release of a real 32-bit operating system kernel. After several beta versions OS/2 2.0 all of a sudden was the best DOS ever. Full exploitation of the 80386 memory modes enabled the simultaneous support of 240 (!) parallel DOS-sessions, each of which were fully compatible with the then current DOS 5.0, including support of EMS- and XMS-memory independetly in each DOS-box. OS/2 2.0 also featured a new object oriented user interface, called workplace shell (WPS), which was entirely based on the presentation manager, and which offered full compatibility with Windows 3.0. In contrast to the earlier versions 1.x, OS/2 2.0 didn't depend on special BIOS support, so every PC with at least a 80386 SX processor and a minimum of 8 MB of memory could run OS/2. Though it was a tremendous step forward, IBM just hadn't done their homework well enough.
Most PC's sold in 1992 were equipped with 2-4 MB of memory, and the need to upgrade to 8 MB was a financial drawback. Meanwhile Microsoft had launched Windows 3.1 and had changed the API's considerably in comparison with 3.0. As a result, the latest versions of Windows applications wouldn't run on OS/2. Meanwhile hardware periferal development advances had introduced screen resolutions beyond the standard 640x480 VGA and advanced printing functions, both of which were not supported in OS/2 yet, because the necessary device drivers were not available. Another new gimmick in Windows, the integrated soundcard support, also was ignored by IBM until then, assuming that sound support was not needed in an office environment.
Against these list of drawbacks, OS/2 had one biiigggg advantage: it was much more stable than the DOS / Windows 3.1 combination.

IBM had listened to the market and launched OS/2 version 2.1 in June 1993. Most of the disadvantages of version 2.0 had been eliminated: vastly improved graphical performance, including support for most videoboards, in various resolutions; addition of a multimedia subsystem, with full support for CD-rom and soundcards; they even were leading in PCMCIA support, by allowing hot swapping of PCMCIA-cards, a feature which wasn't matched by Windows until Windows 2000; and of course they now offered application compatibility with Windows 3.1. They even introduced a special version with SMP support. Only in one area they still didn't match DOS/Windows: to run properly OS/2 2.1 required a minimum of 12 MB of memory, whereas most PC's at the time were only equipped with 4-8 MB.

September 1994 was marked with the arrival of OS/2 version 3.0, this time called OS/2 Warp. Again IBM had concentrated on performance, and reduced the minimum memory requirements to 6 MB, though for smooth operation some more was very welcome. This time the user interface had undergone a major overhaul, and the result was and is, what has made OS/2 beloved by so many users. This version, since March 1995 repackaged as Warp Connect, which included extensive networking and Internet support, is the basis of the OS/2 developments and has proved to be an industrial strength platform for many applications over a long time. Over 40 fixpacks have been released, including several functional enhancements to keep OS/2 Warp version 3 up to date, and only in 2000, this version has started to become obsolete.

September 1995, Microsoft managed to force IBM to cease marketing OS/2 (see legal case), but this didn't end OS/2 history at all.
November 1996, IBM released OS/2 Warp version 4.0 (code name Merlin), at the time the most advanced Operating System for PC's ever and first matched by Microsoft with Windows XP. Among the many new features were: Open GL, True-type, integrated speach control (Voice type), integrated Java support, and many smaller improvements and beautifying things. OS/2 version 4 requires a 80486 processor and a minimum of 16 MB (more recommended), but back in 1996 this was not any more considered a problem. OS/2 version 4 has been maintained by IBM until now by a total of 15 fixpacks sofar. Fixpacks beyond 12 even upgrade OS/2 version 4.0 to the next release !

Despite tremendous marketing repression by Microsoft, IBM released OS/2 version 4.5 Warp Server for e-Business (code name Aurora) May 1999, again with a rich list of enhancements and improvements, that brings OS/2 in front of competition. The most important improvements this time were the Logical Volume Manager (which eliminates the restriction to 26 drive letters) standard SMP support for up to 64 processors, and a new filesystem, JFS, which allows files and partitions up to 2 TB, and allows fast recovery after a diskfailure.
IBM still continues to add new hardware support and to produce fixpacks and convenience packs, which are repackaged versions of OS/2 with the latest fixpacks preapplied, so despite the silence in marketing OS/2 is fully alive and continues to be a viable choice for many users.

The newest development now is coming from Serenity systems, who licensed OS/2 and created a new distribution called eComstation. eComstation version 1.0 was released August 2001 (NLS versions following soon) and includes of fully supported copy of OS/2 Warp version 4.51 along with a wealth of application software, some of which makes the bundle a real bargain. To put it bluntly: OS/2 just started its 2nd life !

Latest update: December 30th 2001