Monthly Archives: March 2017

OS/2 2.0 at 25

Posted on March 31, 2017 by Michal Necasek

Twenty-five years ago, on March 31st, 1992, IBM released OS/2 2.0, the first mass-market 32-bit PC operating system. The road to OS/2 2.0 was quite long and winding, and the OS was a proud member of the vaporware club (just like, … Continue reading →

Posted in 386, IBM, Microsoft, OS/2 | 34 Comments

Something New Every Day…

Posted on March 26, 2017 by Michal Necasek

Apparently in 1990, Intel still sold complete systems, and they were PC compatible at that point. And perhaps not surprisingly, Intel also OEMed MS OS/2 1.21: And there was this cute ASCII-art logo: There very little customization that Intel did, … Continue reading →

Posted in Intel, OS/2 | 14 Comments

There’s More to the 286 XENIX Story

Posted on March 22, 2017 by Michal Necasek

It turns out that there is a rather interesting story behind the 286 XENIX incompatibility with 386 and later processors. Here’s roughly what happened in chronological order. In 1982, Intel released the iAPX 286 processor, later known as the 80286 or simply 286. This … Continue reading →

Posted in 286, 386, Intel, Microsoft | 42 Comments

PCI Corner Case

Posted on March 20, 2017 by Michal Necasek

Last weekend I had the pleasure of debugging a curious case of older PCI configuration code (circa 2005) failing on newer (post-2010) hardware. The code was well tested on many 1990s and 2000s PCs (and some non-PCs) with PCI/AGP/PCIe and never … Continue reading →

Posted in Bugs, Intel, PCI | 11 Comments

IBM XENIX: Two Steps Forward

Posted on March 16, 2017 by Michal Necasek

There are reasons to revisit an old topic. Very old, considering that IBM Xenix 1.0 was released in 1984, well over 30 years ago. To recap, this version of Xenix is unique in that it runs only on 286 processors. It … Continue reading →

Posted in 286, IBM, VirtualBox, Xenix | 22 Comments

Tales From the Xenix Crypt

Posted on March 13, 2017 by Michal Necasek

What does Xenix have to do with the Enigma machine? Perhaps surprisingly, there is a clear connection… When reconstructing 386 Xenix 2.2.3, the libmdep.a library proved to be a particularly tough nut to crack. That is because it’s one of … Continue reading →

Posted in SCO, Software Hacks, Xenix | 17 Comments

What a Coincidence

Posted on March 11, 2017 by Michal Necasek

Timeline: Mid-1988: SCO 386 Xenix 2.2.3 is released 1996 (probably): Someone dumps the 386 Xenix 2.2.3 disks, but enough sectors are missing that the OS is impossible to install January 3rd, 2013: OS/2 Museum posts about the damaged Xenix dump February … Continue reading →

Posted in PC history, Xenix | 1 Comment

Oldest Surviving 386 PC OS?

Posted on March 9, 2017 by Michal Necasek

Four years ago, the Xenix 2.2.3 mystery cropped up (twice). The issue has been revisited and thanks to Michael Casadevall, an enthusiastic reader, came to a happy conclusion: 386 Xenix version 2.2.3 was finalized in late June 1988 (the newest … Continue reading →

Posted in 386, Microsoft, SCO, UNIX, Xenix | 24 Comments

More Data on CF to IDE to SCSI

Posted on March 6, 2017 by Michal Necasek

To get a better picture of the performance of the CF to IDE to SCSI solution, I moved the Adaptec 1542C into one of my favorite boards, the Alaris Cougar with a classic Intel 486 DX2 OverDrive CPU. For a … Continue reading →

Posted in 486, CompactFlash, IDE, Storage | 16 Comments