Power Controller

The PowerBook G4 computer can operate from a 15 volt power outlet on an airline, but for safety reasons, the computer will not allow battery charging. In order for the computer to detect the connection to airline power, the airline power cable should have a sense resistor of 24.3K ohms connected between the power plug's shell and ground. The PowerBook G4 computer has a new variable speed fan control circuit and a new thermal circuit that will force the unit to sleep if the processor temperature...

Fire Wire Connector

The FireWire connector has six contacts, as shown in Figure 3-2. The connector pin assignments are shown in Table 3-2. Table 3-2 Pin assignments on the FireWire connector Ground return for power and inner cable shield Twisted-pair B, differential signals Twisted-pair B, differential signals Twisted-pair A, differential signals Twisted-pair A, differential signals When the computer is on or the power adapter is connected, the power pin provides a maximum voltage of 17 V no load and up to 6 W...

Open Firmware

The software architecture implemented on current Macintosh computers follows the standard defined by the Open Firmware IEEE 1274-1994 specification. Three Technical Notes provide an introduction to Open Firmware on the Macintosh platform. They are TN1061 Open Firmware, Part I, available at TN1062 Open Firmware, Part II, available at TN1044 Open Firmware, Part III, available at Other Technical Notes provide additional information about Open Firmware on the Macintosh. TN2000 PCI Expansion ROMs...

Velocity Engine Alti Vec

Velocity Engine is Apple's name for the AltiVec vector processor in the PowerPC G4 microprocessor. Apple provides support for developers who are starting to use the Velocity Engine in their applications. Documentation, development tools, and sample code are available on the World Wide Web, at vDSP.html Apple Computer, Inc. November 2002 AltiVec Technology Programming Environments Manual AltiVec PEM is a reference guide for programmers. It contains a description for each instruction and...

Memory Controller and Bus Bridge

The Uni-N memory controller and bus bridge IC provides cost and performance benefits by combining several functions into a single IC. It contains the memory controller, the PCI bus bridge, the Ethernet and FireWire interfaces, and the AGP interface. Each of the separate communication channels in the Uni-N IC can operate at its full capacity without degrading the performance of the other channels. In addition to the four buses listed in Table 2-1, the Uni-N IC also has separate interfaces to the...

Keyboard Illustrations

Apple Powerbook Kebord Layout

Figure 3-5 shows the actual appearance of the keyboard. Figure 3-6 shows the alternate modes of operation of the function and control keys. Figure 3-7 shows the embedded numeric keypad. Figure 3-6 and Figure 3-7 include duplicate versions of some keys in order to show their alternate modes of operation. In some cases, the alternate key captions shown in the figures do not appear on the keyboard. For the actual appearance of the keyboard, refer to Figure 3-5. Figure 3-6 Alternate operations of...