Category Archives: Storage

Compaq EXTDISK.SYS

This is a follow-up to a previous post about the curious driver in Microsoft OS/2 1.21. After initially writing the article, additional information came to light, explaining why the code was there. In summer 1988, Compaq released the Deskpro 386/25, … Continue reading

PC Disk Sector Sizes and Booting

Everyone knows that the IBM PC established 512-byte sectors on floppies and hard disks as the standard, which survived for several decades until the advent of “native” 4K-sector drives. Of course what “everyone knows” is not necessarily the whole story. … Continue reading

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

How Not to Erase Data

From past blog posts it is fairly obvious that the OS/2 Museum occasionally purchases used hard disks. Most of the time, the disks are either completely erased (overwritten with zeros) or don’t have anything very interesting on them. But sometimes … Continue reading

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

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

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

Centaur Close-ups

Readers have expressed interest in seeing what exactly a Western Digital ‘Centaur’ drive looked like. I took a few photos of a WD95044-A drive, the larger capacity (40 MB) and newer variant of the WD Centaur family. Some photos were … Continue reading

Can This Conner Talk?

As part of research into the IDENTIFY DRIVE command, the OS/2 Museum acquired two old Conner IDE drives, a CP-342 and a CP-341i. These drives look extremely similar at first glance, and they’re both 40 MB IDE drives, but on … Continue reading

Whence IDENTIFY DRIVE?

As most everyone knows, the AT Attachment standard (informally known as IDE) started by literally bolting the previously standalone AT disk controller onto a MFM drive with a ST506 interface and connecting the assembly to the host system with a … Continue reading