Category Archives: 386

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

Shiniest x86 Chip

Posted on January 16, 2017 by Michal Necasek

While there have been many shiny new chips in the metaphorical sense, x86 (and x87) chips have never been known to be literally shiny. The typical packaging is ceramic or some form of brushed metal, and neither of these surfaces is … Continue reading →

Posted in 386, C&T, PC hardware | 11 Comments

Getting Organized, Finally

Posted on December 16, 2016 by Michal Necasek

After years of looking for a good storage solution for 386 chips, I accidentally stumbled upon it: This is a relatively modern CPU tray, designed for—I believe—Socket G processors, It turns out that old ceramic PGA 386s fit in the … Continue reading →

Posted in 386, PC hardware | 11 Comments

Deskpro 386 at 30

Posted on September 26, 2016 by Michal Necasek

30 years ago, in September 1986, Compaq announced the Deskpro 386, a PC as revolutionary as it was conservative. Compaq decided to forge its own path and not wait for IBM to introduce a 386-based PC. At the same time, Compaq … Continue reading →

Posted in 386, Compaq, IBM, PC history, PC press | 19 Comments

Playing Football

Posted on February 19, 2016 by Michal Necasek

The Super Bowl is long over and it’s time to look at different kind of football. In Winter 1986/1987, Microsoft initiated a small skunkworks project called “Football”. The objective was to take “Sizzle”, a development branch of proto-OS/2 that would eventually … Continue reading →

Posted in 386, IBM, Microsoft, OS/2, PC history | 21 Comments

386 LOADALL

Posted on January 7, 2016 by Michal Necasek

I recently came across hints suggesting that in the 1987 timeframe, Microsoft contemplated the use of the 386 LOADALL instruction in OS/2. As far as I know, no released version of OS/2 (including the SDK betas) utilized the 386 LOADALL. … Continue reading →

Posted in 386, Undocumented | 26 Comments

More on the C&T Super386

Posted on November 20, 2015 by Michal Necasek

Since last week’s post, more information about the Chips and Technologies C&T has come to light. It now appears that at least some 38605DX processors were made. Whether there is any surviving working system is still an open question (since … Continue reading →

Posted in 386, C&T, Documentation | 32 Comments

The Forgotten 386

Posted on November 13, 2015 by Michal Necasek

The CPUs that fit into a 386 socket are well known: Intel’s original, AMD’s exact copy, and Cyrix/TI upgrades. There is also IBM’s 386SLC which is close to a 386 but can’t be plugged into a standard 386 socket. The photo below … Continue reading →

Posted in 386, C&T, PC history | 25 Comments

Fast Unaccelerated VGA?

Posted on October 26, 2015 by Michal Necasek

For the purpose of comparing the relative real-world performance of various processors, it’s useful to run CPU and graphics-intensive benchmarks such as 3DBench or DOOM. To avoid benchmarking the graphics card instead, the VGA has to have enough headroom so … Continue reading →

Posted in 386, ATi, S3, VGA | 27 Comments

The Nearly Ultimate 386 Board

Posted on October 5, 2015 by Michal Necasek

Spurred by the acquisition of a 386 ZIF socket adapter, I revived the semi-mysterious 386 board acquired over a year ago. To recap, the board is unusual in that it has CPU frequency configurable via jumpers, but I had trouble getting anything … Continue reading →

Posted in 386, Hardware Hacks, PC hardware | 9 Comments