Category Archives: PC history

DOS 2.11 From Scratch

Warning: Long post! After having good luck with rebuilding core PC DOS 1.1 from source code, I thought I’d do the same with the DOS 2.11 source code released by the CHM. What follows is largely a collection of notes … Continue reading

Posted in Development, DOS, Microsoft, PC history | 36 Comments

PC DOS 1.1 From Scratch

A number of years ago, the Computer History Museum together with Microsoft released the source code for MS-DOS 1.25 (very close to PC DOS 1.1) and MS-DOS 2.11. I never did anything with it beyond glancing at the code, in … Continue reading

Posted in Development, DOS, Microsoft, PC history | 24 Comments

Learn Something Old Every Day, Part III

As part of a hobby project, I set out to reconstruct assembly source code that should be built with an old version of MASM and exactly match an existing old binary. In the process I learned how old MASM versions … Continue reading

Posted in Assembler, Development, Microsoft, PC history | 11 Comments

PC-86-DOS

A number of years ago, an 8″ disk containing Seattle Computer Products (SCP) 86-DOS 1.0 was successfully imaged. The newest files on the disk are dated April 30, 1981, making the disk the oldest complete release of what was soon … Continue reading

Posted in Development, DOS, IBM, PC history | 18 Comments

The Dual-Drive IDE Hell

I have perhaps inaccurate but very strong memories from my PC-building days (in the early to mid-1990s) that one of the most failure-prone and frustrating endeavors was trying to get two IDE drives working together on a single cable as … Continue reading

Posted in IDE, PC hardware, PC history | 20 Comments

Drive Price Mystery

While digging into the history of DoubleSpace and DriveSpace, I came across a handy article about the rocky relationship between Stac Electronics and Microsoft. Only I was distracted by the bold claim (certainly claimed in very bold letters) that a … Continue reading

Posted in PC history, Storage | 14 Comments

The IBM PC, 41 Years Ago

No, the OS/2 Museum does not have either a time machine or difficulty doing basic math. As of this writing, it is August 2021 and the IBM PC was announced in August 1981, 40 years ago. But in August 1980, … Continue reading

Posted in 8086/8088, BIOS, DOS, IBM, Intel, PC hardware, PC history | 60 Comments

IDENTIFY Ancient DRIVE

This article will attempt to collect IDENTIFY DRIVE dumps from antique IDE drives, with running commentary. For the purposes of this list, “antique” is defined as a drive model released in 1990 or earlier, typically with the drive itself also … Continue reading

Posted in IDE, PC hardware, PC history, Storage | 9 Comments

Learn Something Old Every Day, Part II

The ultimate reason why I pulled out the old Seagate ST-225 drive was because I wanted to try connecting it to the Western Digital WD1003-IWH board that I recently acquired. The WD1003-IWH is a curious evolutionary half-step between ST506 interface … Continue reading

Posted in IDE, PC hardware, PC history, Storage | 11 Comments

Learn Something Old Every Day

More or less by accident I found myself writing a very basic DOS utility to read data off of an IDE drive. It started out by just issuing the IDENTIFY DRIVE command and capturing the data, but adding the ability … Continue reading

Posted in Documentation, PC hardware, PC history, Seagate, Storage | 3 Comments