OS/2

Kyu OhKevin Koo

Matt LiberatiStephanie Engel

History of OS/2

• Version 1• Version 2• Warp 3• Warp 4

Version 1

• Version 1.0 was released in 1987– IBM and Microsoft produced OS/2 version 1.0– Processor 286

• Version 1.1 was released in 1988– Presentation Manager (PM)

• Version 1.2 was released in 1989

– Improved PM

• Version 1.3 was released in 1991 rectangle – smaller, faster, and more stable than previous

versions.

Version 2

• Version 2.0 was released in 1992

– first 32 bit operating system for personal computers

– used Virtual DOS Machines (VDMs) – Workplace Shell (WPS)

• Version 2.1 was released in 1993– more CD-ROM and SCSI drivers

Warp 3

• Warp 3 was release in 1995• Required 4 MB of RAM• Improved Workplace Shell in

performance and functionality• TCP/IP and Internet

communications

Warp 4

• Warp 4 was released in 1996• new features

– Java– VoiceType Navigation – Dictation

• “Universal Client” because of its unparalleled network connectivity.

Today OS/2 Server

• Current version 4.51• IBM product• Runs on Intel, Cyrix, AMD pentium,

and Intel• Cost $250

Semaphore

• What is it• 3 Types

Scheduling

• Multitasking• Priority Based

Deadlock

• Definition• Situation• Result

Graphical User Interface

• The Beginnings of OS/2

• OS/2 Warp 4

• OS/2 was originally written for the 286

• The first version of OS/2 was released in late 1987

• The command line interface of OS/2 1.0 looked a

lot like DOS

The Beginnings of OS/2

OS/2 1.0 had a number of important features that DOS did not have - and which many other operating systems began to support only many years later.

• Preemptive multitasking

• Multithreading

• Interprocess communication (IPC)

• Virtual memory support (swapping)

• Fully protected operation

• Dynamic linking (DLLs)

• Support for 16MB physical memory

screenshots from the OS/2 1.0 tutorial program

In OS/2 1.0 there wasn't really much to look at. The interface was text only

The worst obstacle that OS/2 faced was DOS support. This was caused by a combination of several factors:

• No support for virtualization of real mode on the 286 processor.

• Seriously incomplete DOS API forcing applications to access hardware directly.

• Memory constraints of real mode.

OS/2 Warp 4

• Released in August, 1996

• Its new features included a "beautified" GUI; an ex-Apple programmer designed the new graphical icons

• A full Java Development Kit, which included a Java Virtual Machine

• OS/2 Warp 4 is fully Object Oriented via SOM

• Pre-emptively multitasks all sessions (including DOS/Win)

• Faster than WinNT, more stable than Win95, easier to use than both WinNT and Win95, it is safe proven technology, it runs practically all of your DOS and Windows 3.1 programs

OS/2 Warp 4 desktop with the WarpCenter and some Object Desktop's component

In OS/2 Warp 4, you can run practically all OS/2, Java, DOS, and Win 3.1 programs all at the same time with no problem!

Characteristics

• OS/2 is a single-user operating system

Uses pre-emptive multi-tasking to schedule CPU time

•OS/2 was the first Personal Computer to provide intrinsic multi-tasking

Multi-Threading

•Native applications can utilize multi-threading capability

•Not legacy applications from DOS or Windows 3.1

Differences

OS/2 allows for different AUTOEXEC.BAT files to be set for different DOS applications

Lower end versions of OS/2 either:

• require for Windows 3.1 to already be installed on the computer

• includes a re-compiled version of Win 3.1.