Theory of Operation 4-1
4Theory of Operation4.1 Introduction
This section contains a general block diagram theory of operation description of the
Extensa 900 Series Notebook Computers.
Note: Various internal components may change on future models and
busses/bus speeds are subject to change.
4.2 Notebook Functional Overview
The Extensa 900 Series Notebooks consist of eight major functions or sections
including:
♦System Processor — implemented on the Main Board Assembly
♦Memory Subsystem — implemented on the Main Board Assembly
♦I/O Subsystem — implemented on the Main Board Board
♦Keyboard Subsystem — implemented on the Main Board Assembly and the
Keyboard Assembly
♦Video Subsystem — implemented on the Main Board and LCD Display Panel
assemblies
♦Sound Subsystem — implemented on the Main Board Assembly
♦Touchpad Mouse Subsystem — implemented on the Touchpad assembly and
on the Main Board Assembly
♦Hard Disk Drive Subsystem — implemented on the Main Board Assembly and
the Hard Disk Drive Assembly
♦Floppy Disk Drive Subsystem — implemented on the Main Board Board and
Floppy Disk Drive Assembly
♦PCMCIA Controller and Sockets — implemented on the PCMCIA Module and
on the Main Board
♦Power Subsystem — implemented on the Main Board, the battery pack, and
the AC adapter