IBM RS/6000 - Manual (Page 30)

Macro Power Management
This uses system software to control the hardware. Macro Power
Management is, by far, the more powerful technique and thus is the
basis for the PReP Power Management model.
1.3 The PowerPC Microprocessor Common Hardware Reference
Platform (CHRP)
This section introduces the PowerPC Microprocessor Common Hardware
Reference Platform, previously referred to within the industry as Common Hardware
Reference Platform (CHRP), and describes the purposes and the goals of this
platform.
To avoid using the platform's long name, the industry has assigned a nickname to
this specification, PowerPC Platform.
Before talking about the platform itself, we want to give you a brief introduction
about the history, rationale and reasons why this platform had to be developed.
1.3.1 PowerPC Platform - Introduction and History
The PowerPC family of microprocessors, which is being jointly developed by Apple,
IBM and Motorola, is the foundation for an established and rapidly expanding
market for RISC-based systems. Apple Computer has shipped well over one
million Power Macintosh computers since March 1994. IBM has made major
announcements for a full line of PowerPC systems, thus completing its successful
PowerPC-based workstation and server products. Motorola has introduced a broad
range of desktop and server systems. Other companies, such as Bull, Canon and
FirePower, have announced or shipped PowerPC-based systems.
The PowerPC systems shipped by Apple retain many legacy characteristics of
Macintosh hardware and software. The existing PowerPC systems shipped by IBM
and Motorola retain many legacy characteristics of Intel-based PC design. The
operating systems on which the applications run are not compatible with the
different hardware platforms. This incompatibility causes hardware manufacturers
and software developers to have to choose platform families, and this limits the
options available to users.
To correct the problems facing customers and developers, Apple, IBM and Motorola
looked at various ways of combining the two hardware architectures into a common
system architecture. In November 1994, Apple, IBM and Motorola agreed to
develop a specification for a common hardware platform with the purpose of
defining a system which will become the pervasive open industry standard for
single users and on up through to server configurations. Finally, on November 13,
1995, the three companies announced the availability of the PowerPC Platform.
1.3.2 The PowerPC Platform Document
The PowerPC Platform is a set of specifications that defines a unified personal
computer architecture and brings the combined advantages of the Power Macintosh
platform and the standard PC environment to both system vendors and users.
These open specifications will make it easier for system vendors to design
computers capable of running multiple operating systems. Operating systems from
6 Introduction to PCI-Based RS/6000 Servers