Apple Desktop Computer manual Software, Rtas

Page 5

Placing the Computer Face Down				42
Removing the bottom cover			43
Unfastening the Cables		43
Removing the Retaining Screws			45
Removing the Logic Board Assembly				46
Removing the EMI Shield		46
Locations of the Expansion Slots			47
Main RAM Expansion	48
Mechanical Design of RAM SO-DIMMs				49
Electrical Design of RAM SO-DIMMs				49
SDRAM Devices	50
Conﬁguration of RAM SO-DIMMs				51
Address Multiplexing		52
RAM SO-DIMM Electrical Limits			52
Video RAM Expansion	53

Chapter 5 Software		55
Why Make This Change?				56
What Has Changed				57
Features of the New Approach					58
Performance			59
RAM Footprint			59
User Experience				59
Data Structures and Files					59
Compatibility			59
Boot ROM Contents				60
POST Code		60
Open Firmware			61
Mac OS 'ndrv' Drivers				61
RTAS	61
Toolbox Image File Contents					62
Open Firmware Script				62
Trampoline Code			63
ToolBox ROM Image				63
NewWorld Boot Process				63
What Is Different			64

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Contents Apple iMac Computer Page Contents RAM Expansion Devices and PortsRtas SoftwareRtas NV-RAM Appendix Abbreviations IndexFigures and Tables Page About This Developer Note Contents of This NoteSupplemental Reference Documents PowerPC G3 MicroprocessorMac OS ATA DevicesOpen Firmware USB DevicesE F a C E Introduction Features Shows a front view of the computer Case and External FeaturesFront view 2Side view showing I/O bay System Software Compatibility IssuesUSB Ports and Devices Main RAM Expansion ModulesVideo RAM Expansion Modules Page Architecture Architecture Backside Cache Processor moduleG3 Microprocessor Controller IC Main Logic BoardMemory Controller and PCI Bridge Built-in Modem USB ControllerVideo Display Subsystem Infrared Link Module Devices and Ports USB Ports USB ConnectorsGND Transfer Types SupportedADB Compatibility USB Compatibility IssuesMacintosh-To-Macintosh Connections Serial Port CompatibilityUSB Storage Devices USB ControllerKeyboard Layout KeyboardKeyboard and USB MouseVideo Display Hard Disk DriveSound System Infrared Communication LinkSound Outputs Sound InputsBuilt-in Microphone External Sound InputHeadphone Jacks Sound SpeciﬁcationsExternal Sound Output Total harmonic distortion Internal Modem Ethernet PortPage RAM Expansion Placing the Computer Face Down Removing the Logic Board AssemblyExpansion Slots Unfastening the Cables Removing the bottom coverRAM Expansion Removing the Retaining Screws 3Logic board assembly handle and retaining screwsRemoving the EMI Shield Removing the Logic Board AssemblyLocations of the Expansion Slots 6Locations of the RAM expansion slots Main RAM ExpansionElectrical Design of RAM SO-DIMMs Mechanical Design of RAM SO-DIMMsSdram Devices Conﬁguration of RAM SO-DIMMs Address Multiplexing RAM SO-DIMM Electrical LimitsVideo RAM Expansion Page Software Why Make This Change? What Has Changed Features of the New Approach RAM Footprint PerformanceUser Experience Data Structures and FilesBoot ROM Contents Rtas Mac OS ndrv DriversToolbox Image File Contents ToolBox ROM Image NewWorld Boot ProcessTrampoline Code Interrupt Handling What Is DifferentRAM Footprint Outmoded ResourcesStartup Disk Control Panel NanoKernelMachine Identiﬁcation Open Firmware and the Device TreeInterrupt Layout Software Abbreviations Chrp NMI Page Index Nvram X, Y, Z Allen Watson