ATA BIOS Limitation

Product Notice

To:      All Quantum Customers
Product: ATA (IDE)hard drives greater than 2.1GB
Subject: BIOS Support for logical cylinder values>4095
Date:    2/26/96

Issue:

Some system BIOS may not accept logical cylinder values greater than 4095.

Background:

Recently, during compatibility testing of new (>2.1GB) Quantum ATA drives, it was discovered that certain system BIOS had difficulty translating ATA (IDE) drives with more than 4095 logical cylinders. ATA hard drives greater than 2.1GB will typically have a logical cylinder value greater than 4095 (i.e. the Quantum Bigfoot 2.5GB uses CHS values of 4994, 16, 63). These systems experienced symptoms such as not reporting the correct drive capacity (in CMOS and / or FDISK), locking up during the system power-on self-test (POST), or reporting a hard disk controller failure during a system reset. These problems would typically occur after manually entering the drive CHS values in the system setup (CMOS) or during the system / IDE host adapter auto-detection process. Internal testing has determined these issues are system BIOS related and not a result of the hard drive logical geometry (CHS values).

Solution:

The best solution is to contact the motherboard or BIOS manufacturer for system BIOS upgrade availability. Another solution that has been proven to work in many cases is the Ontrack Disk Manager software that is licensed to Quantum. The Disk Manager software is included in the Quantum User Information Package (UIK) that is shipped in each multi-pack.