Technical information

CHAPTER 2
Architecture
Main Logic Board 27
The graphics controller IC is an ATI Rage LT Pro. It contains 2D and 3D
acceleration engines, a digital video port, front-end and back-end scalers, a CRT
controller, and a PCI bus interface with bus master capability.
For information about the display, see “Flat Panel Display” in Chapter 3,
“Devices and Ports.” For information about external monitors and projection
devices, see “External Monitors” also in Chapter 3.
Power Management Unit 2
The power manager IC is a 68HC05 microprocessor, also called the Cuda PMU.
It operates with its own RAM and ROM. The functions of the Cuda PMU
include:
■ controlling the sleep and power on and off sequences
■ controlling power to the other ICs
■ controlling the brightness of the display
■ supporting the ADB interface to the built-in keyboard and trackpad
■ monitoring the battery charge level
■ controlling battery charging
Sound Interface IC 2
The sound interface IC, called Screamer, is a custom IC that combines a
waveform amplifier with a 16-bit digital sound encoder and decoder (codec). It
is similar to the AWAC IC used in older PowerBook models, with three main
differences:
■ It has better analog performance
■ It has a low-power mode
■ It includes a separate input used for the modem call progress sound from a
PC Card modem.
The Screamer IC is not soldered directly to the main logic board but is on a
small card mounted on the main logic board. The sound outputs from the
Screamer IC are connected to a pair of LM4861 power amplifier ICs that provide
power to drive the speakers.