Category Archives: PC history

The A20-Gate: It Wasn’t WordStar

Although WordStar was long suspected to be the reason (or at least one of the major reasons) for implementing the A20 gate hardware on the PC/AT and all the associated problems later on, it is now all but certain that … Continue reading

Posted in 286, IBM, Microsoft, PC history, WordStar | 29 Comments

Pascal Out Of Memory

Suppose you want to run the original 1981 vintage IBM Pascal 1.0 (supplied by Microsoft) on a PC that is less than 30 years old. Upon execution, PAS1.EXE may well fail with the following error: Error: Compiler Out Of Memory … Continue reading

Posted in Bugs, Corrections, IBM, Microsoft, PC history | 38 Comments

WordStar Again

While trying to work on my DOS 5.0 article, I looked at DOS 5.0 build 224 from June 1990, which is the oldest surviving beta of DOS 5.0. And the README contains the following intriguing text, which reminded me of … Continue reading

Posted in DOS, PC history, WordStar | 74 Comments


For several years now I’ve been trying to continue the DOS history series and write (or rather finish) a DOS 5 page. While tracing the history of DOS 1.0 or 2.0 is quite difficult and the amount of source material … Continue reading

Posted in DOS, PC history, Random Thoughts | 12 Comments

About That Warranty…

Readers have been wondering what kind of valuable warranty users of Microsoft’s Quick Pascal 1.0 (and other products) might be voiding by running it on top of DR DOS 3.3x or 3.40. I don’t have the original Quick Pascal 1.0 … Continue reading

Posted in Digital Research, Microsoft, PC history, Undocumented | 16 Comments

How Apple Created Hackintosh, Part II

There is every indication that throughout the early 2000s, Apple internally built and ran all of OS X on x86 PCs (it’s also something Steve Jobs himself mentioned in 2005). Otherwise why would Apple have x86 drivers for AC’97 audio … Continue reading

Posted in Apple, Intel, OS X, PC history, Pre-release | 10 Comments

How Apple Created Hackintosh, Part I

At a developer conference in June 2005, Apple announced that OS X will transition from PowerPC to Intel processors. The first Intel Macs (sometimes nicknamed “Mactels”) were introduced several months later, in January 2006. The announcement generated significant interest in … Continue reading

Posted in Apple, Intel, PC history, Pre-release | 10 Comments

MS KB Articles

A recent blog post over at explores some of the mysteries surrounding information that at one point or another was published as a Microsoft KnowledgeBase article (or a KB article for short). It’s not entirely clear where the KB … Continue reading

Posted in Documentation, Microsoft, PC history | 17 Comments

Audio Frequency Data Acquisition

Readers of this blog may have noticed that besides OS/2 software, I have interested in PC sound cards. I thought I had a decent idea about the major milestones in PC sound history, but I had to perform a few … Continue reading

Posted in IBM, MCA, PC hardware, PC history, PS/2, Sound, Sound Blaster | 14 Comments

SYSENTER, Where Are You?

It has only recently been brought to my attention that Intel’s SYSENTER/SYSEXIT instructions have rather unusual past, and their origin is shrouded in mystery and confusion. One facet of the usage of these instructions is also a little unorthodox. Depending … Continue reading

Posted in Intel, PC history, Undocumented | 12 Comments