Category Archives: Development


Certain older Microsoft software (including Windows font files) contains mysterious strings starting with “mtswslnk”, sometimes longer and sometimes shorter. This led some people to wild speculation about the meaning and purpose of the string. Let’s start with the full string: … Continue reading

Posted in Development, Microsoft, PC history | 2 Comments

OS/2 Programmer’s Toolkit

For those wishing to write OS/2 1.x programs, the complete Microsoft OS/2 Programmer’s Toolkit documentation is now online. This is Microsoft’s programming documentation for OS/2 1.0 programming. It is worth noting that IBM’s programming documentation was different; worse yet, IBM’s … Continue reading

Posted in Development, Documentation, Microsoft, OS/2 | 2 Comments

Book Review: Linkers & Loaders

A Few Decades Late Book Reviews Linkers & Loaders, by John R. Levine Morgan Kaufmann Publishers, October 1999; 256 pages, ISBN 1-55860-496-0; $60.95 Published in 1999, Linkers & Loaders is one of the more recent books reviewed in this series. … Continue reading

Posted in Books, Development | 1 Comment

Master Builders of OS/2

The MS OS/2 videos exhibit has now been completed with the addition of two PDF documents. These are scans of two fat three-ring binders that were handed out to attendees of the Microsoft OS/2 Developer’s Conference in New York City … Continue reading

Posted in Development, Microsoft, OS/2 | 11 Comments

Windows NT BSOD Aclock Port

Do you remember the famous Windows NT Blue Screen Of Death? For years it was a source of jokes and bad reputation of Windows reliability. There even was a Blue Screen Saver! Today we fortunately see much less of it, but it … Continue reading

Posted in 386, Development, NT, VGA, Windows, x86 | 10 Comments

No comments in source code? Really?

A few weeks ago I came across an interview with an academic software researcher, now working for Microsoft. (Unfortunately the interview was in a non-English print publication, so I can’t link to it.) The interview was quite interesting, far better … Continue reading

Posted in Development | 14 Comments

Book Review: DOS Internals

A Few Decades Late Book Reviews DOS Internals, by Geoff Chappell Addison-Wesley, March 1994; 768 pages, ISBN 0-201-60835-9; $39.95 DOS Internals is a very unusual book. Written by an academic whose field isn’t computer science, it is a in-depth and … Continue reading

Posted in Books, Development, DOS, Microsoft | 6 Comments

Phantom 3.0

As previously mentioned, the OS/2 Museum adapted the Phantom redirector example from the second edition of Undocumented DOS to demonstrate that the redirector interface was already fully implemented in the August, 1984 release of PC DOS 3.0, a fact apparently … Continue reading

Posted in Development, DOS | 35 Comments


Prior to 1991, Microsoft did not sell MS-DOS to end users directly. Although MS-DOS 3.2 (1986) and later was available to system builders as a “packaged product”, most PC users would get an OEM version of MS-DOS with a new … Continue reading

Posted in Development, DOS, Microsoft | 10 Comments

Watcom Win386

When Windows 3.0 came out in 1990, the press loved it and users bought it in droves. Unfortunately, technically it was at best a step sideways, and Windows 3.0 was the cause of many sleepless nights for application developers. Even … Continue reading

Posted in 386, Development, Windows | 11 Comments