iMac (Early 2009): External features, ports, and connectors
Learn about the external features, ports, and connectors on the iMac (Early 2009) computers. All ports and connectors covered in this document are located on the Input/Output (I/O) panel on the bottom-right side on the back of the computer.
Features
Built-in microphone
The internal microphone operates independently from all other audio input ports and is always available. The internal microphone supports recording at bit depths of 16, 20, or 24 bits per sample and at sample rates of 44.1 kHz, 48 kHz, or 96 kHz. Audio recorded from the microphone is presented as a stereo data stream with the same data on both the left and right channels. The microphone gain can be adjusted from -16 dB to +30 dB.
Built-in iSight camera
Video chat using iChat AV over a broadband connection, take pictures using Photo Booth, or capture video through iMovie HD. The camera has an indicator light that glows when the iSight camera is in use.
Slot-loading optical disc drive
The SuperDrive can read CD-ROM, photo CD, audio, and DVD discs. It can write to CD-R, CD-RW, DVD±R, DVD±RW, and DVD±R Double-Layer (DL) discs.
Built-in infrared (IR) receiver for Apple Remote
The infrared-based Apple Remote (sold separately) works with the built-in IR receiver for use with Front Row to access DVD Player, iPhoto, iTunes, and QuickTime Player.
I/O ports
Apple Mini DisplayPort video output port
Using the Mini DisplayPort video output port, you can mirror video or extend the size of the Mac OS X desktop (extended desktop mode) with a compatible DVI (Digital Visual Interface) display or VGA (Video Graphics Display) or projector using the appropriate Mini DisplayPort adapter:
For Single Link DVI displays, use the Mini DisplayPort to DVI Adapter (MB570Z/A).
For Dual-Link DVI displays, use the Mini DisplayPort to Dual-Link DVI Adapter (MB571Z/A).
For VGA displays or projectors use the Mini DisplayPort to VGA Display Adapter (MB572Z/A).
Video mirroring
With video mirroring, you can see the image that is on the iMac flat-panel display on an external monitor, television, or projector.
Extended desktop mode
Connect an external display and use that area in addition to the built-in display for your desktop.
Ethernet port (10/100/1000 Base-T)
The iMac (Early 2009) has a built in Ethernet port for 10Base-T/UTP, 100Base-TX and 1000Base-T Gigabit operation. You can connect your iMac to an Ethernet cable from a cable or DSL modem, hub, switch, or router, or to another Macintosh computer.
The connected device can be either a 10Base-T, 100Base-T or 1000Base-T device; the port automatically detects which type of device is connected. You don't have to use an Ethernet crossover cable to connect to other Ethernet devices.
Four USB (Universal Serial Bus) 2.0 ports
The back of the iMac (Early 2009) has a total of four USB 2.0-compliant ports. You can connect both USB 2.0- and USB 1.1-compliant devices to these ports. The USB 2.0 ports support both low-speed, full-speed, and high-speed data transfers, at up to 1.5 megabits per second (Mbit/s), 12 Mbit/s, and 480 Mbit/s respectively.
The aluminum Apple keyboard contains a USB hub with two high-speed USB 2.0 ports.
All the USB ports use USB Type A connectors, which have four pins each.
Audio line input/optical digital audio input port
Line input
The analog line input operates independently from all other audio input ports and is always available. The line input supports recording at bit depths of 16, 20, or 24 bits per sample and at sample rates of 44.1 kHz, 48 kHz, or 96 kHz. Audio recorded from the line input is presented as a stereo data stream. You can adjust the line input gain from -16 dB to +30 dB.
During input of a 1 kHz, 1 VRMS (-3 dBFS) sine wave (44.1 kHz input sample rate, 24-bit sample depth, 0.0 dB input gain, no weighting) the audio line input has the following nominal specifications:
Jack type: 3.5 mm (1/8-inch) stereo
Maximum input voltage: 3 VRMS (+11.8 dBu)
Minimum voltage input for full scale output: 63 mVRMS (-21.5 dBu) at input gain = +30 dB
Input impedance: > 20 kilohm
Frequency response: 20 Hz to 20 kHz, +0.5 dB/-3 dB
Signal-to-noise ratio (SNR): >90 dB
Total harmonic distortion + noise (THD+N): <-85 dB (0.006%)
Channel separation: > 85 dB
Optical digital input
The digital audio input has the following electrical characteristics (nominal specifications), based on input of a 1 kHz sine wave at 0 dBFS input level, 24-bit sample depth, and 44.1 kHz sample rate (unless otherwise specified below):
FSI – input sample rates: 44.1 kHz, 48 kHz, or 96 kHz
Bits per sample: 16, 20, or 24
Signal-to-noise ratio (SNR): >130 dB
Total harmonic distortion + noise (THD+N): <-130 dB (0.0003%)
Sound output/digital audio output port
Line/Headphone output
The headphone output is automatically selected for audio output if no external S/PDIF optical digital output device is detected. The headphone output supports a stereo data stream at bit depths of 16, 20, or 24 bits per sample and at sample rates of 44.1 kHz, 48 kHz, or 96 kHz. The headphone output volume can be adjusted from 0.0 dB to -64 dB.
During playback of a 1 kHz sine wave at -3 dBFS voltage level, 24-bit sample depth, 44.1 kHz output sample rate, 100 k load (unless otherwise specified) the audio output has the following nominal specifications:
Jack type: 3.5 mm (1/8-inch) stereo combo
Maximum output voltage: 1.6 VRMS (+6.3 dBu)
Output impedance: <24 ohms
Frequency response: 20 Hz to 20 kHz, +0.5 dB/-3 dB
Signal-to-noise ratio (SNR): >90 dB
Total harmonic distortion + noise (THD+N): <-80 dB (0.007%)
Channel separation: >85 dB
S/PDIF optical digital output
The S/PDIF (Sony/Philips Digital Interface Format) optical digital output is automatically selected when an S/PDIF optical digital output device is detected on the external combination audio port. The S/PDIF optical digital output supports pulse-code modulation (PCM) and Arc Consistency Algorithm #3 (AC-3) audio formats with the following stereo data stream characteristics:
PCM: 16, 20, or 24 bits per sample at sample rates of 44.1 kHz, 48 kHz, or 96 kHz
AC-3: 16 bits per sample at sample rates of 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, or 192 kHz
The S/PDIF optical output channel status conforms to International Electrotechnical Commission (IEC) 60958-3 consumer mode digital audio.
During playback of a 1 kHz sine wave (S/PDIF output format at 0 dBFS output level, 44.1 kHz sample rate, 24-bit sample depth, unless otherwise specified) the digital audio output has the following nominal specifications:
Jack type: 3.5 mm (1/8-inch) stereo combo
Digital audio signal-to-noise ratio (SNR): >130 dB
Digital audio total harmonic distortion + noise (THD+N): <-130 dB (0.00003%)
FireWire port
The iMac has one FireWire 800 port supported by an Open Host Controller Interface (OHCI) FireWire controller with a FireWire 800 PHY (Physical Layer). The FireWire 800 port supports IEEE 1394b with a maximum data rate of 800 Mbps (100 MBps). The iMac (Early 2009) works with 7W for the port.
The iMac (Early 2009) computer supports Target Disk Mode (TDM).