Background; Scope; Definitions; Boot To Dos - HP Xw6400 - Workstation - 4 GB RAM Overview

Background

In new technology transitions, support for some legacy features is often difficult to manage or remove.
In the transition from PATA to SATA optical devices, many companies, including HP, have issues
regarding drivers that enable legacy DOS and DOS-based utilities. This paper details various issues
relating to the transition from PATA to SATA optical disc drives and provides several workarounds.
Using DOS functionality to image hard drives is one of the features of particular interest to users.
Depending on the workstation and the configuration, a variety of workarounds are described in this
paper. Notably, the simplest workaround is using a USB drive key to initiate the process. Using a
drive key might be the most effective solution because of its increased use, continued capacity
expansion, and reduced price.

Scope

This document is intended to help consolidate all of the known issues and workarounds concerning
the transition from PATA optical disc drives to SATA optical disc drives with the primary purpose of
covering the ability to use bootable DOS CD-ROMs for imaging and troubleshooting.

Definitions

Boot to DOS

Boot to DOS is the ability to use a Bootable CD-ROM to boot into a DOS environment. This does not
include the ability to assign a drive letter to the CD-ROM drive.

Bootable DOS CD-ROM

There are several ways to create a bootable CD. The most common way is to use floppy emulation.
The CD-ROM is recognized and boots in the same manner that a floppy disk does. You can also use
no emulation or hard drive emulation to create a bootable CD.

Disk On Key (DOK)

A USB flash drive that is capable of booting a computer into a DOS or WinPE environment that has
been correctly configured.

DOS CD-ROM driver

The DOS CD-ROM driver is loaded as a device in config.sys. It creates a named 'driver' to be used
by a DOS CD-ROM redirector, such as mscdex.exe, to provide drive letter access. The most common
DOS CD-ROM driver is oakcdrom.sys. This driver will detect and address most PATA optical disc
drives. In most cases oakcdrom.sys will not detect SATA optical disc drives (with the exception of
when SATA emulation is set to Combined IDE Controller mode). There are 3rd party drivers available
on the Internet that will detect and address SATA optical disc drives.
Drive letter access (DLA)
Drive letter access is used to assign a drive letter in DOS to a CD-ROM drive. This enables access to
the data on the extended area (not the bootable area) of a CD-ROM. There are two components
required for accessing the extended area of a CD-ROM. You must have a DOS CD-ROM driver, such
as oakcdrom.sys, and a DOS CD-ROM redirector, such as mscdex.exe.