Category Archives: ESDI

IDENTIFY ESDI DRIVE

Posted on May 25, 2022 by Michal Necasek

As previously mentioned on this site, the IDENTIFY DRIVE command in the ATA specification almost certainly first appeared in ESDI controllers supplied to Compaq by Western Digital. Since I have now finally secured a working ESDI hard disk, I could … Continue reading →

Posted in ESDI, IDE, PC hardware, PC history, Western Digital | 19 Comments

Learn Something Old Every Day, Part V: Early IBM PS/2 Hard Disks

Posted on May 1, 2022 by Michal Necasek

So I have been (again) trying to properly archive old MS OS/2 SDKs. The version 1.02 SDK from December 1987 (corresponding to OS/2 1.0) turned out to be a bit of a poser. The SDK came on both 3.5″ and … Continue reading →

Posted in ESDI, IBM, PC history, PS/2 | 16 Comments

WD1007V Commands

Posted on June 5, 2021 by Michal Necasek

While researching material for a previous article, I wanted to examine the only AT-compatible ESDI controller I have, a Western Digital WD1007V-SE2. My board was made in 1990, the firmware is from 1989, and the controller was likely introduced in … Continue reading →

Posted in Debugging, Documentation, ESDI, Western Digital | 3 Comments

It Was a Problem Back in the Day

Posted on May 19, 2021 by Michal Necasek

Several years ago, I found out the hard way that old versions of DOS have trouble with hard disks with more than 17 sectors per track. To recap, DOS versions older than 3.3 may hang when booting from a hard … Continue reading →

Posted in Bugs, DOS, ESDI, Storage | 26 Comments