Jump To:
Leopard Technical Q&As
Apple provides information hardware developers can use to create products that are compatible with Macintosh computers and programming interfaces software developers can use to create software that drives or accesses devices.

A guided learning path for hardware and driver developers new to Mac OS X.   Essential information for developing drivers and device-access software.   API references organized by framework.
Document Descriptions
On Off
Display

Sort by
Title
Sorted by
Topic
Sort by
Date
What are configuration variables in Open Firmware? (HTML) (日本語 HTML)
HW38: Defines the configuration variables in Open Firmware.
Networking 1999-02-15
What are snag keys in Open Firmware? (HTML) (日本語 HTML)
HW35: Explains Open Firmware snag keys, including examples of their function.
Networking 1999-02-15
The "/aliases" node in the device tree (HTML)
HW89: Describes the aliases node in the Open Firmware device tree.
Open Firmware 2000-09-05
The AAPL, slot-name property and PCI (HTML) (日本語 HTML)
HW61: Discusses the use of the AAPL,slot name property for PCI
Open Firmware 1999-04-19
Are the Name Registry device tree nodes unique? (HTML)
Deprecated - HW64: Discusses whether Name Registry nodes copied from the Open Firmware device tree are unique.
Open Firmware 1999-10-11
Can you explain the words "begin" and "again"? (HTML)
HW70: Explains the Forth looping words "begin" and "again" and how to escape such a loop.
Open Firmware 1999-10-11
Changing the configuration variable in Open Firmware (HTML) (日本語 HTML)
HW40: Tells how to change the configuration variable in Open Firmware.
Open Firmware 1999-02-15
DDR SDRAM ICs for PowerBooks and iBooks that use Memory bus slewing (HTML)
QA1344: Specifies DDR SDRAM IC optimization for PowerBooks and iBooks that use Memory bus slewing.
Open Firmware 2004-03-18
Determining Open Firmware version (HTML)
HW100: Demonstrates how to find out the version of Open Firmware on your Macintosh.
Open Firmware 2000-10-06
Difference between an Open Firmware word and method (HTML) (日本語 HTML)
HW46: Describes the differences between an Open Firmware word and an Open Firmware method.
Open Firmware 1999-02-15
Disabling Processor Cores on a Multi-Core System (HTML) (日本語 HTML)
QA1141: Describes how to disable processor cores on a multi-core system for testing purposes.
Open Firmware 2008-09-16
IODeviceTree and the I/O Registry (HTML) (日本語 HTML)
QA1120: Describes the IODeviceTree plane in the Mac OS X I/O Registry.
Open Firmware 2008-09-18
Locating the 1275-1994 Standard Document (HTML)
HW85: Alerts that the Open Firmware (IEEE 1275-1994) document can't be found at the IEEE Standards Association site.
Open Firmware 2000-07-17
Switching between one and two machine mode for the Open Firmware user interface (HTML) (日本語 HTML)
HW37: Explains how to change from one machine mode to two in the Open Firmware user interface.
Open Firmware 1999-02-15
Using "words" in Open Firmware (HTML)
HW73: Explains how to search for specific entries within all the global and local Open Firmware words.
Open Firmware 1999-10-11
Was that a path I just saw? (HTML)
HW101: Describes the Open Firmware path that is occasionally shown at boot time.
Open Firmware 2000-10-06
What are generic names in Open Firmware? (HTML) (日本語 HTML)
HW34: Documents the generic names in Open Firmware.
Open Firmware 1999-02-15
What is a tokenizer? (HTML) (日本語 HTML)
HW58: Defines a tokenizer.
Open Firmware 1999-03-29
What is an Open Firmware devalias? (HTML)
HW99: Describes devaliases in Open Firmware.
Open Firmware 2000-10-06
What is an Open Firmware phandle, and why can't I access it from the Mac OS? (HTML)
HW76: Explains an "Open Firmware phandle" and why it is inaccessible from the Mac OS.
Open Firmware 1999-11-15
What is the return stack in Open Firmware and can I use it? (HTML)
HW67: Describes the purpose of the Open Firmware return stack and how developers can use it.
Open Firmware 1999-10-11
The "/aliases" node in the device tree (HTML)
HW89: Describes the aliases node in the Open Firmware device tree.
PCI and PC Card 2000-09-05
The AAPL, slot-name property and PCI (HTML) (日本語 HTML)
HW61: Discusses the use of the AAPL,slot name property for PCI
PCI and PC Card 1999-04-19
Allocating and sharing memory with user space from an I/O Kit driver (HTML) (日本語 HTML)
QA1197: Describes the preferred technique for allocating and sharing buffers in an I/O Kit kernel driver.
PCI and PC Card 2008-10-13
Are the Name Registry device tree nodes unique? (HTML)
Deprecated - HW64: Discusses whether Name Registry nodes copied from the Open Firmware device tree are unique.
PCI and PC Card 1999-10-11
Avoiding Kernel Event Conflicts (HTML)
QA1063: Documents the namespace for the vendor_code field of the kern_event_msg structure.
PCI and PC Card 2001-09-14
Can you explain the words "begin" and "again"? (HTML)
HW70: Explains the Forth looping words "begin" and "again" and how to escape such a loop.
PCI and PC Card 1999-10-11
The "chosen" node in the device tree (HTML)
HW88: Describes how to find the "chosen" node in the Open firmware device tree.
PCI and PC Card 2000-09-05
Determining Open Firmware version (HTML)
HW100: Demonstrates how to find out the version of Open Firmware on your Macintosh.
PCI and PC Card 2000-10-06
Difference between an Open Firmware word and method (HTML) (日本語 HTML)
HW46: Describes the differences between an Open Firmware word and an Open Firmware method.
PCI and PC Card 1999-02-15
Difference between using Restart or Shut Down in the Finder's Special menu in Open Firmware (HTML) (日本語 HTML)
HW47: Explains the differences between using Restart or Shut Down on Open Firmware
PCI and PC Card 1999-02-15
Displaying PCI Configuration Registers contents in Open Firmware (HTML)
QA1036: Demonstrates how to display PCI Configuration Resister contents in Open Firmware.
PCI and PC Card 2001-05-18
Do PowerBooks have a PCI bus? (HTML) (日本語 HTML)
HW43: Explains that a Powerbook has a PCI bus.
PCI and PC Card 1999-02-15
The dreaded "incompatible flag -framework" error (HTML)
QA1096: Explains how to eliminate the incompatible flag -framework error in Project Builder.
PCI and PC Card 2001-12-05
Energy Star PCI Device (HTML) (日本語 HTML)
QA1108: Provides useful information for developers of Energy Star-compliant PCI devices.
PCI and PC Card 2002-01-15
ExpressCard Prevents System Sleep (HTML)
QA1517: Describes how some ExpressCard cards can prevent system sleep and how to fix the problem.
PCI and PC Card 2007-02-28
Generating a Non-Maskable Interrupt (NMI) (HTML) (日本語 HTML)
QA1264: Explains how to generate a non-maskable interrupt (NMI) on modern Macintosh systems.
PCI and PC Card 2008-10-13
The "green" PCI bus (HTML)
HW93: Explains why the PCI bus is considered "green".
PCI and PC Card 2000-09-05
How can I tell if a PCI device has on board I/O space? (HTML)
QA1287: Demonstrates "how to" tell if a PCI device has on board I/O space.
PCI and PC Card 2003-09-24
How many PCI header types exist today? (HTML)
HW92: Briefly describes the three PCI header types defined in the PCI 2.2 specification.
PCI and PC Card 2000-09-05
Installing an I/O Kit KEXT Without Rebooting (HTML)
QA1319: Describes the state of the art of installing I/O Kit kernel extensions (KEXTs) without requiring a restart.
PCI and PC Card 2003-10-28
IODeviceTree and the I/O Registry (HTML) (日本語 HTML)
QA1120: Describes the IODeviceTree plane in the Mac OS X I/O Registry.
PCI and PC Card 2008-09-18
IOKit Framework Headers (HTML) (日本語 HTML)
QA1107: Describes the differences between the headers in IOKit.framework and the I/O Kit headers in Kernel.framework.
PCI and PC Card 2002-01-15
IOLog and Interrupt Context (HTML) (日本語 HTML)
QA1100: Describes when IOKit runs at primary (hardware) interrupt context.
PCI and PC Card 2002-02-13
Issues with boot time KEXT loading (HTML) (日本語 HTML)
QA1087: Explains how to solve problems with loading KEXTs at boot time.
PCI and PC Card 2004-01-15
Legacy Devices (HTML)
HW84: Discusses why legacy devices with hard-wired I/O addresses may not work properly with Open Firmware.
PCI and PC Card 2000-03-20
Locating the 1275-1994 Standard Document (HTML)
HW85: Alerts that the Open Firmware (IEEE 1275-1994) document can't be found at the IEEE Standards Association site.
PCI and PC Card 2000-07-17
Making sense of IOKit error codes (HTML) (日本語 HTML)
QA1075: Explains how to interpret I/O Kit error codes.
PCI and PC Card 2002-02-07
Open Firmware device tree nodes (HTML)
HW86: Explains the usage of the "@n" notation in Open Firmware device tree nodes.
PCI and PC Card 2000-09-05
Open Firmware Memory bus speed (HTML)
HW97: Describes a method to display memory bus speed for G3 or G4 Macintosh in Open Firmware.
PCI and PC Card 2000-09-22
The "packages" node in the device tree (HTML)
HW90: Describes the "packages" node in the Open Firmware device tree.
PCI and PC Card 2006-02-22
PCI address/data stepping (HTML)
HW94: Explains that Apple does not support PCI address/data stepping.
PCI and PC Card 2000-09-05
PCI bus on the iMac (HTML) (日本語 HTML)
HW42: Explains that the iMac has a PCI bus even though it has no expansion slots.
PCI and PC Card 1999-02-15
PCI class codes (HTML)
HW91: Explains why PCI class codes are important.
PCI and PC Card 2000-09-05
PCI Header types (HTML)
HW78: Describes the three required types of PCI headers to be provided in its configuration header space.
PCI and PC Card 1999-11-15
PCI Macintoshes and CardBus controllers (HTML)
HW87: Explains why older PCI Macintoshes do not recognize a Cardbus controller.
PCI and PC Card 2000-09-05
PCI SIG (HTML) (日本語 HTML)
HW55: Describes the meaning of the acronym PCI SIG.
PCI and PC Card 1999-03-29
PCI/PCI-X slots on the Power Mac G5 (HTML)
QA1307: Discusses installing PCI/PCI-X cards of different speeds in the Power Mac G5.
PCI and PC Card 2003-09-30
Power Management; Policy Maker vs. Power Controller (HTML) (日本語 HTML)
QA1121: Describes the differences between a Power Management Policy Maker and a Power Management Power Controller.
PCI and PC Card 2002-02-13
Sleep vs. Doze on Mac OS X (HTML)
QA1309: Discusses and demonstrates sleep versus doze detection on Machintosh Mac OS X
PCI and PC Card 2003-10-09
Using "words" in Open Firmware (HTML)
HW73: Explains how to search for specific entries within all the global and local Open Firmware words.
PCI and PC Card 1999-10-11
Was that a path I just saw? (HTML)
HW101: Describes the Open Firmware path that is occasionally shown at boot time.
PCI and PC Card 2000-10-06
What are configuration variables in Open Firmware? (HTML) (日本語 HTML)
HW38: Defines the configuration variables in Open Firmware.
PCI and PC Card 1999-02-15
What are generic names in Open Firmware? (HTML) (日本語 HTML)
HW34: Documents the generic names in Open Firmware.
PCI and PC Card 1999-02-15
What is a CardBus host bus adapter HBA? (HTML)
HW79: Explains what a CardBus host bus adapter (HBA) is and discusses its implementation on the Macintosh.
PCI and PC Card 1999-11-15
What is a tokenizer? (HTML) (日本語 HTML)
HW58: Defines a tokenizer.
PCI and PC Card 1999-03-29
What is an Open Firmware devalias? (HTML)
HW99: Describes devaliases in Open Firmware.
PCI and PC Card 2000-10-06
What is an Open Firmware phandle, and why can't I access it from the Mac OS? (HTML)
HW76: Explains an "Open Firmware phandle" and why it is inaccessible from the Mac OS.
PCI and PC Card 1999-11-15
What is the return stack in Open Firmware and can I use it? (HTML)
HW67: Describes the purpose of the Open Firmware return stack and how developers can use it.
PCI and PC Card 1999-10-11
When to use PCMCIA, PC Card, and CardBus (HTML)
HW77: Explains the differences between PCMCIA, PC Card, and CardBus.
PCI and PC Card 1999-11-15
Working with Configuration Variables (HTML) (日本語 HTML)
QA1119: Explains how to delete a specific Open Firmware configuration variable without using Command-Option-P-R.
PCI and PC Card 2002-02-13
Bluetooth Radio Power Class for Apple Systems (HTML) (日本語 HTML)
QA1278: Notes Preferred Bluetooth Transmitter Characteristics for products designed for Apple Systems.
Performance 2003-08-06
Determining RAM size & location in New World Machines (HTML)
QA1065: Demonstrates Open Firmware method of determining RAM size & location in New World Machines.
Performance 2001-08-01
Determining the version of Open Firmware on your Mac (HTML) (日本語 HTML)
HW60: Describes a method to display the version of Open Firmware on a Macintosh.
Performance 1999-03-29
Disabling Processor Cores on a Multi-Core System (HTML) (日本語 HTML)
QA1141: Describes how to disable processor cores on a multi-core system for testing purposes.
Performance 2008-09-16
Displaying PCI Configuration Registers contents in Open Firmware (HTML)
QA1036: Demonstrates how to display PCI Configuration Resister contents in Open Firmware.
Performance 2001-05-18
DRAM DIMM power pin connections for Macintosh Computers (HTML) (日本語 HTML)
QA1271: Discusses design considerations for DRAM DIMM power pin connections for Macintosh Computers.
Performance 2003-07-04
Empty Memory Objects (HTML) (日本語 HTML)
QA1259: Describes how two memory management edge cases are handled by the common Mac OS memory allocators.
Performance 2003-04-21
Energy Star PCI Device (HTML) (日本語 HTML)
QA1108: Provides useful information for developers of Energy Star-compliant PCI devices.
Performance 2002-01-15
Explanation of SDRAM configuration Nomenclature (HTML)
HW75: Explains the three-part "Device configuration" numbers for SDRAM in the Power Mac G4 Computer Developer Note.
Performance 1999-10-18
Faster DDR DRAM in the 867MHz Power Mac G4 (Mirrored Drive Doors) (HTML) (日本語 HTML)
QA1191: Confirms the use of faster DDR DRAM in the 867MHz Power Mac G4 (Mirrored Drive Doors).
Performance 2002-08-19
Generating a Non-Maskable Interrupt (NMI) (HTML) (日本語 HTML)
QA1264: Explains how to generate a non-maskable interrupt (NMI) on modern Macintosh systems.
Performance 2008-10-13
How can I tell if a PCI device has on board I/O space? (HTML)
QA1287: Demonstrates "how to" tell if a PCI device has on board I/O space.
Performance 2003-09-24
How do I change the numeric base for the Open Firmware user interface? (HTML)
HW66: Explains how to change the numeric base for the Open Firmware user interface.
Performance 1999-10-11
How do I determine the top of the Open Firmware dictionary? (HTML)
HW69: Explains how to determine the top of the Open Firmware dictionary.
Performance 1999-10-11
Installing an I/O Kit KEXT Without Rebooting (HTML)
QA1319: Describes the state of the art of installing I/O Kit kernel extensions (KEXTs) without requiring a restart.
Performance 2003-10-28
IOKit Framework Headers (HTML) (日本語 HTML)
QA1107: Describes the differences between the headers in IOKit.framework and the I/O Kit headers in Kernel.framework.
Performance 2002-01-15
Menu Bar Clock and NVRAM (HTML)
QA1102: Explains why booting with the Command-Option-P-R keys doesn't reset date and time preferences.
Performance 2001-12-21
Open Firmware version number (HTML)
HW96: Discusses the unique values of Open Firmware version numbers.
Performance 2000-09-22
OTScheduleDeferredTask When Task Running (HTML) (日本語 HTML)
NW52: Describes what happens when you use OTScheduleDefferedTask to schedule a task that is running.
Performance 1997-10-13
The "packages" node in the device tree (HTML)
HW90: Describes the "packages" node in the Open Firmware device tree.
Performance 2006-02-22
PC100 SDRAM DIMMs on the Flat Panel iMac (HTML) (日本語 HTML)
QA1130: Describes PC100 SDRAM DIMM limitations on the "original " Flat Panel iMac.
Performance 2002-03-18
PCI class codes (HTML)
HW91: Explains why PCI class codes are important.
Performance 2000-09-05
PCI Header types (HTML)
HW78: Describes the three required types of PCI headers to be provided in its configuration header space.
Performance 1999-11-15
PCI Macintoshes and CardBus controllers (HTML)
HW87: Explains why older PCI Macintoshes do not recognize a Cardbus controller.
Performance 2000-09-05
Power adapter Sensing for the 17" PowerBook (HTML) (日本語 HTML)
QA1266: Details Design and detection considerations for 17-inch PowerBook power adapters
Performance 2003-06-12
Resetting NVRAM to factory defaults (HTML)
QA1103: Describes what happens when you boot holding the Command-Option-P-R keys.
Performance 2001-12-21
A SCSI little secret (HTML)
HW81: Details what to expect when accessing the motherboard SCSI bus on the Blue & White G3.
Performance 1999-12-20
SDRAM Problems With Self-Powered USB Devices (HTML) (日本語 HTML)
HW82: Alerts that non-compliant, self-powered USB devices plugged into a G4, can cause problems with low-voltage-sensitive SDRAM .
Performance 2003-08-21
SDRAM, CAS Latency for the (HTML)
QA1071: Describes the supported CAS Latency values for the "QuickSilver", PowerMac G4 CPUs.
Performance 2001-09-13