Author Archives: Michal Necasek

DOS APPEND

Posted on December 20, 2024 by Michal Necasek

For a long time, I couldn’t quite grasp what the DOS APPEND command could possibly be good for. Until I came across a situation which APPEND was made for. When I worked on organizing and building the DOS 2.11 source … Continue reading →

Posted in DOS, IBM | 46 Comments

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 | 21 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

IBM PC 5150 Model Numbers

Posted on September 24, 2024 by Michal Necasek

Recently I came across a minor mystery—the model numbers of the original IBM PC. For such a pivotal product, there is remarkably little detailed original information from the early days. When IBM started selling the PC, it used two methods … Continue reading →

Posted in IBM, PC hardware, PC history | 27 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 | 32 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

Finally in Xsight

Posted on August 15, 2024 by Michal Necasek

For a long time, I have tried to find a GUI environment running on SCO XENIX (because, honestly, what could be more useless?). Back in the day, meaning late 1980s and early 1990s, SCO sold Xsight, which was an adaptation … Continue reading →

Posted in SCO, X11, Xenix | 21 Comments

Missing XENIX Disks

Posted on July 22, 2024 by Michal Necasek

The previously mentioned warez mega dump contains disk images of SCO 286 XENIX 2.1.0. The release appears to be from February 1986. It is the oldest SCO 286 XENIX release that I know of. But there’s a hitch. The warez … Continue reading →

Posted in 286, Archiving, SCO, Xenix | 33 Comments