Category Archives: 386

There’s More to the 286 XENIX Story

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 | 34 Comments

Oldest Surviving 386 PC OS?

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 | 21 Comments

Booting Is Hard

So I had this brilliant idea of using SCSI drives with old 286/386/486 boards which have old BIOSes that can’t handle IDE drives bigger than 500-ish megabytes. The SCSI HBA is the first one I happened to grab, an Adaptec 1542C … Continue reading

Posted in 386, BIOS, CompactFlash, DOS, SCSI | 16 Comments

IBM XENIX 1.0 Incompatibility Details

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 | 19 Comments

Shiniest x86 Chip

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 | 6 Comments

Getting Organized, Finally

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 | 10 Comments

Deskpro 386 at 30

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 | 17 Comments

Playing Football

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 | 16 Comments

386 LOADALL

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 | 25 Comments

More on the C&T Super386

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 | 26 Comments