Category Archives: OS/2

Stack Checking on OS/2

Posted on November 19, 2024 by Michal Necasek

A while ago I was involved in debugging a seemingly simple yet mysterious problem: A piece of code (a fairly simple interface DLL) built with the Open Watcom compiler was failing with a bogus stack overflow error. The mystery was … Continue reading →

Posted in Debugging, Development, OS/2, Watcom | Leave a comment

Programming NetBIOS on OS/2

Posted on October 23, 2024 by Michal Necasek

Recently I spent some time trying to understand a piece of networking code, and it turned out to be far more difficult than it should have been. The code in question is the NetBIOS interface of C-Kermit and was originally … Continue reading →

Posted in Development, Documentation, IBM, Microsoft, Novell, OS/2 | 12 Comments

OS/2 TCPBEUI Name Resolution

Posted on October 8, 2024 by Michal Necasek

Sometimes I have the following problem to deal with: An OS/2 system uses NetBIOS over TCP/IP (aka TCPBEUI) and should communicate with a SMB server (likewise using TCPBEUI) on a different subnet. This does not work on OS/2 out of … Continue reading →

Posted in IBM, Networking, OS/2, TCP/IP | 49 Comments

OS/2 2.0 Commitments

Posted on September 23, 2024 by Michal Necasek

Last week the OS/2 Museum received a rather interesting donation: a thick spiral bound document titled Third party commitment to IBM’s OS/2 Version 2.0, and labeled IBM COMDEX/SPRING ’92. The binder is a collection of about 250 press releases that … Continue reading →

Posted in IBM, Marketing, OS/2, PC history | 8 Comments

OS/2 2.11 SMP Woes

Posted on September 8, 2024 by Michal Necasek

IBM OS/2 V2.11 for Symmetric Multiprocessing (OS/2 2.11 SMP) was released in mid-1994 in response to Windows NT and its SMP support. The package was nothing more (and nothing less) than OS/2 V2.11 with support for SMP hardware. It was … Continue reading →

Posted in IBM, OS/2, PC history, SMP | 31 Comments

Digging Into OS/2 2.0

Posted on September 8, 2024 by Michal Necasek

The other day I had a “pressing” need to obtain the list of modules loaded in an OS/2 VM by examining the VM’s memory and CPU state. I was able to use existing code that worked on OS/2 V3.0 (Warp) … Continue reading →

Posted in Debugging, Documentation, IBM, OS/2 | 21 Comments

More MS OS/2 2.0

Posted on June 30, 2024 by Michal Necasek

Over the last few weeks, two “new” pre-releases of OS/2 2.0 have been found in ancient warez archives. The first is OS/2 2.0 build 6.64, released in early April 1990: In general, this build is not substantially different from the … Continue reading →

Posted in IBM, Microsoft, OS/2, Pre-release | 5 Comments

The Future That Never Was

Posted on March 4, 2024 by Michal Necasek

Microsoft OS/2 2.0 SDK Pre-Release 2, June 1990 In 1990, the strategic PC operating system of Microsoft and IBM was not DOS, not Windows, but OS/2. The first 16-bit OS/2 was initially released in 1987 with a reduced feature set, … Continue reading →

Posted in 386, IBM, LAN Manager, Microsoft, OS/2, PC history, Pre-release | 76 Comments

Retro-Porting to OS/2 1.0

Posted on July 20, 2023 by Michal Necasek

A few weeks ago I embarked on a somewhat crazy side project: Make the Open Watcom debugger work on OS/2 1.0. This project was not entirely successful, but I learned a couple of things along the way. The Open Watcom … Continue reading →

Posted in Development, IBM, Microsoft, OS/2, Watcom | 10 Comments

Slovenian OS/2 Warp 4

Posted on September 11, 2022 by Michal Necasek

This is a guest post written by Marko Štamcar from the Slovenian Computer Museum in Ljubljana. Additional context and commentary from the OS/2 Museum can be found at the end of the article. Slovenia being a tiny country with a … Continue reading →

Posted in IBM, OS/2, PC history | 22 Comments