(1.2) Differences Between Versions

What are the differences between versions?

• IBM OS/2 Warp, Version 3 is the newest and most advanced version of OS/2 ever created. This release is aimed squarely at the rapidly growing home and small business software market. Yet, in addressing the concerns of these demanding consumers, it offers significant advantages to the large number of traditional IBM and OS/2 users, including those in big businesses and government. A few of the enhancements include a BonusPak of full fledged applications (including one button access to the Internet), the LaunchPad, many more device drivers, and significant performance improvements. Please see (0.4) Special Report on OS/2 Warp for more information.
• IBM OS/2 Version 2.1 is the previous release of OS/2, which added Windows 3.1 compatibility, multimedia support (including software motion video), and more device drivers. With Version 2.1 IBM ended the practice of including extra features in its own, preinstalled versions of OS/2 that were not found in the off-the-shelf package. OS/2 2.1x and OS/2 for Windows propelled OS/2 into the mainstream PC marketplace. The latest Service Pak for OS/2 2.1 is level 06300.
• IBM OS/2 Version 2.0 is the first release of OS/2 which will run only on machines with an 80386SX processor or better. With this release IBM started developing OS/2 (and its Intel and non-Intel-based successors) independently but continued to involve third party PC manufacturers in its testing. Improvements included an object-oriented Workplace Shell (WPS); a multiple operating system boot mechanism; better DOS and Windows support [see (1.3) DOS and Windows Compatibility]; new 32-bit programming interfaces; support for more than 16 MB of physical RAM [see (2.6) More Than 16 MB RAM]; and more third party device drivers. OS/2 1.x applications, unmodified, still run under OS/2 2.0 (and later).
• IBM OS/2 Version 1.3 is the last release of OS/2 to operate on PCs with 80286 CPUs. This version introduced built-in Adobe Type Manager (ATM) [see (5.5) Adobe Type Manager], providing scalable typefaces for screen and printer. Procedures Language/2 (REXX), a powerful batch-oriented programming language, became a part of Standard Edition with this release. [See (5.11) REXX.] (A few vendors are shipping Microsoft OS/2 Version 1.3, but Microsoft has ceded all OS/2 development to IBM.)
• OS/2 Version 1.2 was the first to incorporate the High Performance File System (HPFS) [see (1.5) High Performance File System]. With this release IBM OS/2 added a dual boot mechanism and IBM Extended Edition [see (3.10) Extended Services] introduced REXX.
• OS/2 Version 1.1 was the first to include the Presentation Manager (PM) GUI/API. Microsoft OEM versions added a dual boot mechanism with this release.
• OS/2 Version 1.0, introduced in late 1987, was the first release of OS/2. Task switching was accomplished using a character-based shell and limited DOS compatibility was provided.

Versions of OS/2 from 2.1 on have been made available in two packages: one containing built-in Windows code to run Windows applications (sometimes called the "with Win-OS/2" or "full" package) and the other which can use an existing copy of Windows (optional) to run Windows applications (the "for Windows" or "without Win-OS/2" package).

Related information:

(0.4)  Special Report on OS/2 Warp
(1.1)  What is OS/2 Warp?
(1.3)  DOS and Windows Compatibility
(2.6)  More Than 16 MB RAM
(3.10) Extended Services
(5.5)  Adobe Type Manager
(5.11) REXX