Author Archives: Michal Necasek

mtswslnk

Posted on January 14, 2015 by Michal Necasek

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 Technical Library Scans

Posted on January 10, 2015 by Michal Necasek

After a lot of scanning and OCRing, here’s the OS/2 2.0 Technical Library (well, most of it) in PDF form. This was IBM’s complete programming documentation for OS/2 2.0, covering general programming, GUI development, Workplace Shell, and device drivers. Certainly … Continue reading →

Posted in Documentation, OS/2 | 8 Comments

Book Review: Inside Windows NT

Posted on January 3, 2015 by Michal Necasek

A Few Decades Late Book Reviews Inside Windows NT, by Helen Custer Microsoft Press, 1992; 385 pages, ISBN 1-55615-481-X; $24.95 Inside Windows NT was one of the earliest published books about Windows NT, predating the actual July 1993 release of Windows NT … Continue reading →

Posted in Books, NT | 6 Comments

Ladders and Dragons

Posted on December 28, 2014 by Michal Necasek

While looking at the Windows 95 disk subsystem, something seemed oddly familiar. The nagging feeling was confirmed by the Windows 95 DDK documentation (a file called BLOCK.DOC). The new Windows 95 layered block device driver model called “Dragon” wasn’t all … Continue reading →

Posted in OS/2, PC history, SCSI, Windows 95 | Leave a comment

Curious Instructions

Posted on December 13, 2014 by Michal Necasek

Years ago, Geoff Chappell (the author of DOS Internals, among other things) published an article about mysterious instructions that Microsoft’s LINK knows but Intel’s documentation is silent about. The fourteen listed instructions were: LOADALL, CFLSH, WRECR, RDECR, SVDC, RSDC, SVLDT, … Continue reading →

Posted in Documentation, Intel, x86 | 11 Comments

Windows 8.1 Startup Bugcheck 0xC4

Posted on November 30, 2014 by Michal Necasek

On some systems, both physical and virtual, 64-bit Windows 8.1 as well as Server 2012 R2 consistently crashes with error code (bug check) 0xC4; 64-bit Windows 8 may run on these same systems without trouble. On physical systems, the BSOD … Continue reading →

Posted in Bugs, Microsoft, NT, VirtualBox | 15 Comments

ThinkPad 850 Hardware Maintenance Manual

Posted on November 14, 2014 by Michal Necasek

Thanks to a very helpful reader (Mike Senior—thanks!), the OS/2 Museum can now publish the ThinkPad Power Series 850 Hardware Maintenance Service and Reference manual in the form of a PDF. This is IBM document number 30H2383. The manual might … Continue reading →

Posted in Documentation, PowerPC, ThinkPad | 5 Comments

A Tale of Two Displays

Posted on November 8, 2014 by Michal Necasek

By sheer coincidence, two new computers arrived in my family at almost the same time, and they couldn’t be more different. At first sight, the most striking difference is the quality of their displays, and it says a lot about … Continue reading →

Posted in Apple, Graphics, PC hardware | 11 Comments

Original CEMM Unearthed

Posted on November 5, 2014 by Michal Necasek

An important fragment of PC history was unearthed a few days ago: An image of a Compaq Deskpro 386 supplemental disk from August 1986, containing among other things CEMM.EXE, Compaq’s original expanded memory emulator shipped with the Deskpro 386. The … Continue reading →

Posted in 386, Compaq, DOS | 28 Comments

Site Update

Posted on November 1, 2014 by Michal Necasek

In the past two weeks or so, I’ve been fighting with the site instead of adding content. The hosting company was complaining of too high resource usage on a shared server… but was unable to provide me with detailed access … Continue reading →

Posted in Site Management | 8 Comments