PORTABLE DRIVE DISQUE PORTABLEIMPORTANT NOTICE: Downloading the latest Driver releases helps resolve driver conflicts and improve your computer’s stability and performance.Updates are recommended for all Windows 8, Windows 7, XP and Vista users.Some categories of devices are not currently supported by an I/O Kit family. Take advantage of the Seagate Backup Plus design and upgrade from the included USB 2.0 interface to Thunderbolt technology, FireWire® 800 or USB 3.0 with the additional adapter. For information on using device interfaces, see the document Accessing Hardware From Applications.Install the downloadable HFS+ driver for PC, and use the drive interchangeably between Mac computers and PCs without reformatting. You should seriously consider taking the device-interface approach before attempting to write a kernel-resident driver.Third-party developers should not need to write drivers for the ADB family, except for ADB-USB adaptors.The ATA and ATAPI family provides support for ATA controllers, and access to ATA and ATAPI devices on the ATA bus.Table A-2 Clients and providers of the ATA and ATAPI familyDrives a device that is connected to an ATA bus.An ATA hard drive or an ATAPI DVD-ROM drive. Your driver communicates with its family through an instance of IOADBDevice.ADB bus controller drivers should inherit from the IOADBController class as defined in the header file IOADBController.hCommon client families include the HID family ( IOHIPointing and, IOHIKeyboard classes) and the Graphics family ( IODisplay class).All current ADB bus hardware produced by Apple is well supported by drivers that are included with OS X. Interrupt operations are only supported for kernel-resident clients.Table A-1 Clients and providers of the ADB familyDrives devices that plug into an ADB port.A driver for an ADB mouse is a client of the ADB family but is a member of the HID family (in the IOHIPointing class).An instance of IOADBDevice matches your driver and loads it into the kernel. Only polled mode operations are supported through this library.The Audio HAL is accessed through the Core Audio framework and has its programmatic interface defined in AudioHardware.h in that framework. (The Audio family itself does not provide any MIDI services these are provided by the Core MIDI framework.)The Audio Hardware Abstraction Layer ( Audio HAL) provides all audio services to applications in OS X. The Audio family utilizes a high-resolution time base that is used as the basis for timing information for the entire audio and MIDI system in OS X. It provides a flexible abstraction for audio devices that permits an unlimited number of channels as well as arbitrary sample rates, bit depths, and sample formats. This command object encapsulates all the information necessary to encode a single ATA/ATAPI command as well as the results of the command’s execution.Third-party developers should never need to create a member of the ATA/ATAPI family.The Audio family provides support to enable access to devices that record or play back audio signals. They use the services provided by that object to communicate with the physical device on the bus.Clients of the ATA family must issue ATA/ATAPI commands encapsulated by an IOATACommand object.Copies of the IEEE 1394 specification can be purchased here.Provides a device interface exporting an interface for sending and receiving packets on the FireWire bus and for adding entries into the computer’s own FireWire config ROM.Table A-4 Clients and providers of the FireWire familyUnit drivers: Drives communication with a unit of a device that plugs into the FireWire bus. A driver that uses the SBP-2 transport protocol is the most common client of the FireWire family.Kernel-resident: Kernel.framework/Headers/IOKit/firewire/Device interface: IOKit.framework/Headers/firewireIEEE—. For example, a driver for a PCI audio card will be a client of the PCI family.The FireWire family provides support for, and access to, devices attached to the FireWire bus (FireWire is an Apple trademark applied to the IEEE 1394 standard, also sometimes known as i.LINK™).The FireWire family has strong affinities with the SBP2 family. Use the Core Audio framework to access Audio HAL.Either records or plays back audio signals.PCI audio cards, external USB or FireWire audio devices and any other device that produces or consumes audio.An audio driver must contain subclasses of both IOAudioDevice and IOAudioEngine.An audio driver is a client of other families that provide access to the hardware that the driver supports. An audio driver does not have to call PMinit, joinPMtree, registerPowerDriver, or PMstop, because the Audio family takes care of initializing power management, attaching the driver into the power plane and registering it with power management, and terminating power management.Although an audio driver does not have to implement the IOService method setPowerState, it does need to implement the IOAudio method performPowerStateChange to do the work of changing its device’s power state.The Audio family implements idleness determination by keeping track of active audio engines, so a custom audio driver never needs to call activityTickle or determine idleness on its own.Table A-3 Clients and providers of the Audio familyA kernel-resident client is not necessary. Because the Audio HAL is a client of the Audio family, all audio device functionality is available to clients of the Audio HAL.Kernel resident: Kernel.framework/Headers/IOKit/audio/Although this family does not directly export device interfaces, the Audio family does provide a device interface that is used by the Audio Hardware Abstraction Layer (Audio HAL) to access all of the abstractions provided by the Audio family (see description above).The Audio family performs most power management tasks for subclassed device drivers.
Fam Driver Releases HelpsProtocol drivers: An instance of IOFireWireController matches a protocol driver and loads it into the kernel. The driver communicates with the FireWire family through this instance. Protocol drivers: A driver that provides TCP/IP over FireWire.Unit drivers: An instance of IOFireWireUnit, representing a unit found in a device’s configuration ROM, is matched against the driver and it is loaded into the kernel. Dmg monoblockAlso, if your driver matches against a FireWire unit, it is often possible to do some things with the device. However, use of the minimal config ROM is strongly discouraged by Apple. An example might be a driver for a device with a minimal config ROM (that is, with just a vendor ID). Third-party developers generally should not need to write bus-controller drivers for the FireWire family.In some cases, you can write a driver for a FireWire device instead of for a unit. Other layers, such as Carbon Draw Sprockets, provide application access to graphics. However, the Quartz layer arbitrates access to frame buffers from user space through the windowing system or the CGDirectDisplay API.
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