Category Archives: Development

Complications, Complications

Posted on February 19, 2021 by Michal Necasek

The other day someone asked how hard it would be to modify the Open Watcom linker, wlink, to properly support exports from IOPL segments in OS/2 LX modules. Not terribly hard it turned out, all it needed was to emit … Continue reading →

Posted in Development, OS/2, Watcom | 2 Comments

How Old Is OMF?

Posted on July 9, 2020 by Michal Necasek

The Object Module Format (OMF), used by most DOS development tools, and eventually displaced by COFF/ELF in the 32-bit world, is quite old. It is a somewhat strange format because of its age, and it is quite complex, both because … Continue reading →

Posted in Development, Intel, Microsoft, PC history, x86 | 8 Comments

EMM386 and VDS: Not Quite Working

Posted on February 26, 2020 by Michal Necasek

The other day I set out to solve a seemingly simple problem: With a DOS extended application, lock down memory buffers using DPMI and use them for bus-mastering (BusLogic SCSI HBA, though the exact device model isn’t really relevant to … Continue reading →

Posted in Bugs, Development, DOS Extenders | 2 Comments

Realia SpaceMaker

Posted on April 30, 2018 by Michal Necasek

A recent exploration of Microsoft’s EXEPACK posed the question whether EXEPACK was the first executable compressor, at least in the world of PCs. It wasn’t. That distinction almost certainly belongs to Realia SpaceMaker, which was probably released sometime in late … Continue reading →

Posted in Compression, Development, PC history | 12 Comments

Microsoft Editor

Posted on March 11, 2018 by tenox

(This is a guest post by Antoni Sawicki aka Tenox) In a recent blog post I lamented the lack of a good console/cmd/PowerShell text editor for Windows. During the process I made a rather interesting discovery, that in a fact … Continue reading →

Posted in Development, DOS, Editors, Microsoft, NT, OS/2, Source code, Uncategorized | 23 Comments

IBM OS/2 1.x Programming Documentation Added

Posted on April 15, 2016 by Michal Necasek

IBM’s programming documentation (Programming Tools and Information, aka PTI) for OS/2 versions 1.2 and 1.3 has been added. Big thanks to Bob Eager who scanned the originals and converted them to PDF. The documents have been added to the OS/2 … Continue reading →

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

UINT32_C Macro Considered Harmful

Posted on June 26, 2015 by Michal Necasek

The C99 family of INTN_C and UINTN_C macros fills a real gap in the language, but it also lays extremely nasty traps for the unwary. The evolution of how the macros are defined in the C99 language standard shows that … Continue reading →

Posted in C, Development | 2 Comments

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 Programmer’s Toolkit

Posted on July 11, 2014 by Michal Necasek

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

Posted on January 13, 2013 by Michal Necasek

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