Category Archives: IDE

Reading From Void

Recently I came across the following question: What happens when software reads the registers of a non-existent IDE controller? That is, what happens when software reads for example ports in the 1F0h-1F7h/3F6h range (primary IDE channel) when there is no … Continue reading

Posted in BIOS, IDE, PC hardware | 10 Comments

Historical ATA Standard Drafts

After some digging, I discovered that several old drafts of the original ATA standard (later known as ATA-1) have been out in the public all along, or at least for a very long time, cleverly hiding among hundreds of SCSI-related … Continue reading

Posted in IDE, PC history, Storage | 15 Comments

NetWare 3.12 vs. Large IDE Disks

Recently I had an occasion to find out why NetWare 3.12 using the shipped IDE driver (IDE.DSK) behaves, very, very strangely when let loose on disks bigger than about 500MB (a very foolish thing to even try). The driver loaded … Continue reading

Posted in Bugs, IDE, NetWare, PC history | 46 Comments

More Data on CF to IDE to SCSI

To get a better picture of the performance of the CF to IDE to SCSI solution, I moved the Adaptec 1542C into one of my favorite boards, the Alaris Cougar with a classic Intel 486 DX2 OverDrive CPU. For a … Continue reading

Posted in 486, CompactFlash, IDE, Storage | 15 Comments

OS/2 2.0 LA and “Large” IDE Disks

Attempting to boot OS/2 2.0 LA (Limited Availability) on many systems built in the last 20 years often results in the following crash: The trap screen claims there was an exception (Trap 0 or division overflow) in device driver A:, … Continue reading

Posted in IDE, OS/2 | 4 Comments