Category Archives: Xenix

Finally in Xsight

Posted on August 15, 2024 by Michal Necasek

For a long time, I have tried to find a GUI environment running on SCO XENIX (because, honestly, what could be more useless?). Back in the day, meaning late 1980s and early 1990s, SCO sold Xsight, which was an adaptation … Continue reading →

Posted in SCO, X11, Xenix | 21 Comments

Missing XENIX Disks

Posted on July 22, 2024 by Michal Necasek

The previously mentioned warez mega dump contains disk images of SCO 286 XENIX 2.1.0. The release appears to be from February 1986. It is the oldest SCO 286 XENIX release that I know of. But there’s a hitch. The warez … Continue reading →

Posted in 286, Archiving, SCO, Xenix | 33 Comments

Xenix 2.2 vs. VGA

Posted on April 15, 2022 by Michal Necasek

The other day I started wondering why certain old versions of 286 and 386 XENIX look a bit weird in emulation: The characters are cut off, because XENIX sets up an EGA text mode with 8×14 character matrix but uses … Continue reading →

Posted in 286, 386, PC architecture, PC history, VGA, Xenix | 14 Comments

Fox in the Crypt

Posted on January 19, 2019 by Michal Necasek

Some time ago I wrote a bit about examining the “branding” system which was used by XENIX and other SCO products and based on the crypt() UNIX library function. At the time I assumed that only SCO had used this … Continue reading →

Posted in PC history, SCO, Software Hacks, Xenix | 3 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

IBM XENIX 1.0 Incompatibility Details

Posted on February 7, 2017 by Michal Necasek

Some time ago I wrote about IBM PC XENIX 1.0 and why it won’t work on 386 and later processors. Thanks to a kind reader, I’ve been able to analyze the object files used to link the kernel, and I believe … Continue reading →

Posted in 286, 386, Microsoft, Xenix | 21 Comments

IBM XENIX: One Step Forward, One Step Back

Posted on March 29, 2015 by Michal Necasek

A while ago I wrote about why IBM PC XENIX 1.0 can’t work on any CPU other than a 286. But not content to leave well enough alone, I attempted to patch this version of XENIX so that it would … Continue reading →

Posted in 286, 386, IBM, VirtualBox, Xenix | 5 Comments