Category Archives: Microsoft

Nobody Expects…

Posted on April 14, 2021 by Michal Necasek

…the Spanish Inquisition! Well, that too, but also nobody expects that a bland, run-of-the mill Novell NE2000 NDIS driver would crash/hang just because it runs on 486 or later CPUs. I wanted to try the “basic” DOS redirector shipped with … Continue reading →

Posted in 486, Bugs, Intel, Microsoft | 7 Comments

MS LAN Manager NDDK Anyone?

Posted on April 2, 2021 by Michal Necasek

For R&D purposes, I would very much like to get my hands on the circa 1991 Microsoft LAN Manager Network Device Driver Kit which was meant to support the development of NDIS 2.0 drivers. While it is obvious that some … Continue reading →

Posted in Development, DOS, Microsoft, Networking, OS/2 | 10 Comments

Not MSX, Either

Posted on October 7, 2020 by Michal Necasek

Further examining the mystery of boot sectors supposedly starting with byte value 69h, I considered the possibility that the check could have been added for MSX machines. The MSX platform ticks a lot of boxes: It wasn’t 8086 (but rather … Continue reading →

Posted in IBM, Microsoft, PC history | 15 Comments

Really Atari ST?

Posted on September 21, 2020 by Michal Necasek

This blog has previously examined a very very strange code fragment in the BIOS module of DOS. To recap, when deciding whether a boot sector might have a valid BPB, DOS checks whether the first byte is a relative jump … Continue reading →

Posted in DOS, Microsoft, PC history | 18 Comments

Well Hello

Posted on July 14, 2020 by Michal Necasek

So after some furious disassembling, assembling, and linking, things got this far: It took longer than it ought to have because although IDA is great, I couldn’t figure out how to make it work with GW-BASIC’s bizarre segment usage. The … Continue reading →

Posted in Compaq, Microsoft, PC history, Source code | 7 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

GW-BASIC Source Notes

Posted on June 23, 2020 by Michal Necasek

When I learned that Microsoft released the GW-BASIC source code, I was mildly curious to find out what is or isn’t there. The short answer is that there’s a whole lot, but a lot is also missing. Spelling note: Both … Continue reading →

Posted in Microsoft, PC history, Source code | 20 Comments

Those Win9x Crashes on Fast Machines…

Posted on June 2, 2020 by Michal Necasek

It is well known that Win9x variants prior to Windows 98 have a tendency to crash on fast CPUs. The definition of “fast” is of course fuzzy but the problems were known to occur on AMD K6-2 processors running at … Continue reading →

Posted in AMD, Bugs, Intel, Microsoft | 24 Comments

MS OS/2 SDK Document Dump

Posted on January 3, 2020 by Michal Necasek

The Microsoft OS/2 1.0 SDK library section got a big fat update. Over the holidays I managed to finalize and upload about 25 PDFs, some of which have been lying on my NAS in 98% completed state for almost 10 … Continue reading →

Posted in Documentation, Microsoft, OS/2 | Leave a comment

More on NX Insanity

Posted on November 29, 2019 by Michal Necasek

This article was supposed to be published about two years ago but got forgotten and ignored until now. It’s not the only such article. Perhaps it will start a new “better published late than never” series. After looking more closely … Continue reading →

Posted in AMD, Bugs, Intel, Microsoft | 13 Comments