Overview of iMac
This chapter provides an overview of the hardware and software features of the current models of the iMac computer: the 15” Pangea-based configuration and the 17” Intrepid-based configuration. This chapter is structured such that information unique to each configuration is provided in different subsections. The 15” Pangea-based configuration will be referred to as the 15” iMac; the 17” Intrepid-based configuration will be referred to as the 17” iMac.
In this section:
17” iMac New Features
15” iMac Feature Set
17” iMac Feature Set
Comparison of 15” and 17” iMac Features
System Software
17” iMac New Features
New features are listed here with links to the sections that describe them. For a comparison of 15” iMac and 17” iMac features, see Table 1-1.
Processor and speed: The microprocessor in the iMac computer is a PowerPC G4 with a clock speed of 1 GHz. For more information, see “PowerPC G4 Microprocessor.”
Memory: The computer comes with 256 MB of DDR SDRAM installed in an internal standard 186-pin DIMM expansion slot, with a build-to-order option of 512 MB. A second user-accessible slot accepts an SO-DIMM with up to 512 MB. The maximum total memory is 1 GB. For more information, see “The RAM Expansion Modules for Intrepid IC System.”
Display: The iMac has a built-in 17-inch, wide-screen, flat-panel display (measured diagonally). For more information, see “Flat Panel Display.”
System bus: The speed of the system bus is 133 MHz. For more information, see “Memory and I/O Device Controller.”
Hard disk drive: The iMac computer has an internal Ultra ATA /100, 7200 rpm, 80 GB hard disk. For more information, see “Ultra ATA-100 Interface.”
Graphics acceleration: The graphics IC used in the iMac is an NVidia GeForce4 MX. For more information, see “Intrepid IC Video Display Subsystem.”
Video RAM: The video hardware in the iMac includes 64 MB of DDR SDRAM, which supports 3D features and millions of colors in all resolutions. For more information, see “Intrepid IC Video Display Subsystem.”
External video monitor: The external display connector supports mini-VGA, composite, S-video monitors and projectors, and television sets. A video adapter with composite and S-video connectors is available separately. For more information, see “Video Monitor Port.”
AirPort Extreme support (optional): A 54 Mbps AirPort Extreme Card is available as a build-to-order option or as a user-installable upgrade. See “AirPort Extreme Wireless Support (optional).”
Bluetooth support (optional): Bluetooth support is available as a build-to-order option to enable short-range wireless connections between desktop and laptop computers and a host of other peripheral devices. For more information, see “Bluetooth Technology.”
Sound: The iMac computer has external Apple Pro Speakers. For more information, see “Sound System.”
Audio line-in Audio line-in port for self-powered microphones or other audio equipment. For more information, see “Audio Line-in.”
15” iMac Feature Set
Here is a complete list of the features of the 15” iMac computer. Each feature is described in more detail in a later section.
Processor and speed: The microprocessor in the iMac computer is a PowerPC G4 with a clock speed of 800 MHz. For more information, see “PowerPC G4 Microprocessor.”
Cache: The backside 256 MB L2 cache is included on the microprocessor IC and has the same clock speed as the microprocessor. For more information, see “Level 2 Cache.”
Memory: The computer comes with 256 MB of SDRAM installed in an internal standard 168-pin DIMM expansion slot, with a build-to-order option of 512 MB. A second user-accessible slot accepts an SO-DIMM with up to 512 MB. The maximum total memory is 1 GB. For more information, see “RAM Expansion Modules for Pangea IC System.”
Hard disk storage: The built-in hard disk drive is 7200 rpm with a capacity of 60 GB. For more information, see “Hard Disk Drive.”
Combo drive: The 15” iMac has a combination CD-RW/DVD-ROM drive. For more information, see “Combo (CD-RW/DVD-ROM) Drive.”
Display: The iMac has a built-in 15-inch flat-panel display (measured diagonally). For more information, see “Flat Panel Display.”
External video monitor: The external display connector supports mini-VGA. A video adapter for VGA is available separately. For more information, see “Video Monitor Port.”
Graphics acceleration: The video circuits in the iMac use an NVidia GeForce2 MX graphics IC. For more information, see “Pangea IC Video Display Subsystem.”
Video RAM: The video hardware in the iMac includes 32 MB of DDR RAM, which supports 3D features and millions of colors in all resolutions. For more information, see “Pangea IC Video Display Subsystem.”
USB ports: The iMac has five USB ports (two on the keyboard), described in “USB Interface.”
FireWire 400 ports: The iMac computer has two IEEE-1394a FireWire 400 ports, which support transfer rates of 100, 200, and 400 Mbps. For more information, see “FireWire 400 Ports.”
Target Disk Mode: The computer can act like a FireWire storage device connected to another computer. See “Target Disk Mode.”
Modem: The iMac has a built-in V.92 modem with a 56 Kbps data rate. For more information, see “Internal Modem.”
Ethernet: The iMac has a built in Ethernet port for a 10Base-T and 100Base-TX operation. For more information, see “Ethernet Port.”
AirPort support (optional): An 11 Mbps AirPort Card is available as a build-to-order option or as a user-installable upgrade. For more information, see “AirPort Wireless Support (optional).”
Sound: The iMac has a built-in microphone and speaker, a stereo headphone jack, an Apple Speaker minijack, and external Apple Pro Speakers. For more information, see “Sound System.”
Keyboard: The iMac comes with an Apple Pro Keyboard. The keyboard is also a USB hub with two USB ports. For more information, see “Keyboard.”
Mouse: The iMac comes with an Apple Pro Mouse, a USB mouse with optical tracking. For more information, see “Mouse.”
17” iMac Feature Set
Here is a complete list of the features of the 17” iMac computer. Each feature is described in more detail in a later section.
Processor and speed: The microprocessor in the iMac is a PowerPC G4 with a clock speed of 1 GHz. For more information, see “PowerPC G4 Microprocessor.”
Cache: The backside 256 MB L2 cache is included on the microprocessor IC and has the same clock speed as the microprocessor. For more information, see “Level 2 Cache.”
Memory: The computer comes with 256 MB of DDR SDRAM installed in an internal standard 186-pin DIMM expansion slot, with a build-to-order option of 512 MB. A second user-accessible slot accepts an SO-DIMM with up to 512 MB. The maximum total memory is 1 GB. For more information, see and “The RAM Expansion Modules for Intrepid IC System.”
Hard disk storage: The built-in hard disk is 7200 rpm with a capacity of 80 GB. For more information, see “Hard Disk Drive.”
SuperDrive: The iMac has a SuperDrive (CD-RW/DVD-R) drive. For more information, see “SuperDrive (CD-RW/DVD-R).”
Display: The iMac has a built-in 17-inch, wide-screen, flat-panel display (measured diagonally). For more information, see “Flat Panel Display.”
External video monitor: The external display connector supports mini-VGA, composite, S-video monitors and projectors, and television sets. A video adapter with composite and S-video connectors is available separately; and video adapter for VGA is available separately. For more information, see “Video Monitor Port.”
Graphics acceleration: The video circuits in the iMac use an NVidia GeForce4 MX graphics IC. For more information, see “Intrepid IC Video Display Subsystem.”
Video RAM: The video hardware in the iMac includes 64 MB of DDR RAM, which supports 3D features and millions of colors in all resolutions. For more information, see “Intrepid IC Video Display Subsystem.”
USB ports: The iMac has five USB ports (two on the keyboard), described in “USB Ports.”
FireWire 400 ports: The iMac computer has two IEEE-1394a FireWire 400 ports, which support transfer rates of 100, 200, and 400 Mbps. For more information, see “FireWire 400 Ports.”
Target Disk Mode: The computer can act like a FireWire storage device connected to another computer. See “Target Disk Mode.”
Modem: The iMac has a built-in V.92 modem with a 56 Kbps data rate. For more information, see “Internal Modem.”
Ethernet: The iMac has a built in Ethernet port for a 10Base-T and 100Base-TX operation. For more information, see “Ethernet Port.”
AirPort Extreme support (optional): A 54 Mbps AirPort Extreme Card is available as a build-to-order option or as a user-installable upgrade. For more information, see “AirPort Extreme Wireless Support (optional).”
Bluetooth support (optional): Fully-integrated Bluetooth support is available as a build-to-order option to enable short-range wireless connections between desktop and laptop computers and a host of other peripheral devices. For more information, see “Bluetooth Technology.”
Sound: The iMac computer has external Apple Pro Speakers. For more information, see “Sound System.”
Audio line-in The iMac computer has an audio line-in port for self-powered microphones or other audio equipment. For more information, see “Audio Line-in.”
Keyboard: The iMac comes with an Apple Pro Keyboard. The keyboard is also a USB hub with two USB ports. For more information, see “Keyboard.”
Mouse: The iMac comes with an Apple Pro Mouse, a USB mouse with optical tracking. For more information, see “Mouse.”
Comparison of 15” and 17” iMac Features
Table 1-1 provides a quick comparison of the features of the two configurations of the iMac computer.
System Software
Both models of the iMac computer come with Mac OS X version 10.2.3 installed as the default system. For more information about Mac OS X, see the reference listed in “Mac OS X.”
Machine Identification
Apple Computer discourages the targeting of code to specific machine models. However, if it is necessary to identify a machine in order to determine the features of the machine, applications can use the IORegistry with Mac OS X. Or, in many cases, it is feasible to use Gestalt calls to test a machine for specific features.
Asset management software that reports the kind of machine it is run on can obtain the value of the property at Devices:device-tree:compatible in the Name Registry. The model string is the first program-usable string in the array of C strings in the compatible field. For the 15” Pangea-based iMac, the value of the string in the compatible property is PowerMac4,2. For the 17” Intrepid-based iMac, the value of the string in the compatible property is PowerMac6,1.
The string obtained from the compatible property cannot be displayed to the computer user. If it is available, use the result from calling Gestalt ('mnam', &result) where result is a string pointer. This call returns a Pascal style string that can be displayed to the user.
Velocity Engine Acceleration
The Velocity Engine (an implementation of AltiVec) is the vector processing unit in the PowerPC G4 microprocessor. Some system software has been modified to take advantage of the accelerated processing that the Velocity Engine makes possible. System software has also been modified to support low-level operations using the Velocity Engine.
For complete information on the Velocity Engine, refer to the following Apple websites:
http://developer.apple.com/hardwaredrivers/ve/index.html
and
http://developer.apple.com/documentation/Performance/Conceptual/vDSP/vDSP_Library.pdf
For more information, please see the references at “Velocity Engine (AltiVec).”
© 2003 Apple Computer, Inc. All Rights Reserved. (Last updated: 2003-05-09)