Apple Display Connector

Infobox connector
name=Apple Display Connector
type=analog/digital video connector + USB


logo=
caption=ADC cable end
designer=Apple Computer
design_date=
manufacturer=Apple Computer
production_date=
superseded=
superseded_by= DVI
superseded_by_date= June 2004
external=Yes
hotplug=Yes
length=
width=
height=
electrical=
ground=
maximum_voltage=25 V
maximum_current=4.0 A
audio_signal=
video_signal=
data_signal=
data_bit_width=
data_bandwidth=
data_devices=
data_style=
physical_connector=
num_pins=35
pinout_

pinout_caption=
pin1=
pin1_name=25 V Supply
pin2=
pin2_name=25 V Supply
pin3=
pin3_name=LED
pin4=
pin4_name=TMDS Data0–
pin5=
pin5_name=TMDS Data0+
pin6=
pin6_name=TMDS Data0/5 Shield
pin7=
pin7_name=TMDS Data5–
pin8=
pin8_name=TMDS Data5+
pin9=
pin9_name=DDC Data
pin10=
pin10_name=Vsync
pin11=
pin11_name=25 V Return
pin12=
pin12_name=25 V Return
pin13=
pin13_name=Soft Power
pin14=
pin14_name=TMDS Data1–
pin15=
pin15_name=TMDS Data1+
pin16=
pin16_name=TMDS Data1/3 Shield
pin17=
pin17_name=TMDS Data3–
pin18=
pin18_name=TMDS Data3+
pin19=
pin19_name=DDC CLock
pin20=
pin20_name=Clock Return
pin21=
pin21_name=USB Data+
pin22=
pin22_name=USB Data–
pin23=
pin23_name=USB Return
pin24=
pin24_name=TMDS Data2–
pin25=
pin25_name=TMDS Data2+
pin26=
pin26_name=TMDS Data2/4 Shield
pin27=
pin27_name=TMDS Data4–
pin28=
pin28_name=TMDS Data4+
pin29=
pin29_name=Clock+
pin30=
pin30_name=Clock-
pin_custom1_name=C1
pin_name_custom1=
pin_custom1=Analog Blue Video
pin_custom2_name=C2
pin_name_custom2=
pin_custom2=Analog Green Video
pin_custom3_name=C3
pin_name_custom3=
pin_custom3=Analog Horizontal Sync
pin_custom4_name=C4
pin_name_custom4=
pin_custom4=Analog Red Video
pin_custom5_name=C5
pin_name_custom5=
pin_custom5=Analog RGB Return and DDC Return

The Apple Display Connector (ADC) is a proprietary modification of the DVI connector that combines analog and digital video signals, USB, and power all in one cable. Apple used ADC for its LCD-based Apple Cinema Displays and their final CRT displays, before deciding to use standard DVI connectors on later models.

A setup using ADC dramatically reduces the cable clutter behind a computer. USB devices like the keyboard and mouse could be plugged into the display, the display into the host computer using ADC, and a single power cable to the wall from the computer. The result was effectively a single cable wiring the components together.

First implemented in the July 2000 Power Mac G4 and G4 Cube, ADC disappeared from displays in June 2004 when Apple introduced the aluminum-clad 20", 23", and 30" Apple Cinema Displays, which feature separate DVI, USB and FireWire connectors, and their own power supplies. The ADC was still standard on the Power Mac G5 until April 2005, when new models meant the only remaining Apple product with an ADC interface was the single processor Power Mac G5 introduced in October 2004. This single processor Power Mac G5 was discontinued soon after in June 2005.

Compatibility issues

The Apple Display Connector, first debuted in the Apple Studio Display, is incompatible with the standard DVI connector, as was previously used in the PowerBook G4 and the older Power Mac G4. The Apple DVI to ADC Adapter [http://docs.info.apple.com/article.html?artnum=58692] , which cost $149US at launch but is now available for $99US [http://www.apple.com/pr/library/2002/apr/29adapter.html] , takes USB and DVI connections from the computer, together with power, and combines them into an ADC connection, allowing ADC monitors to be used with DVI-based machines.

When ADC was first implemented in some models of Power Mac G4s, Apple also removed all the DVI connectors from these computers, so the previous Mac owners cannot use DVI monitors without using ADC to DVI adapter.

The ADC can only carry 100 W of power, so it could not run the 19-inch or bigger CRTs that were widely available during ADC's debut, nor can it run contemporary flat panels marketed for home entertainment (many of which support DVI or VGA connections). The power limit was an important factor for Apple to abandon ADC when it launched the 30-inch Apple Cinema HD Display. Power is supplied to the ADC port by a finger connector on the video card, which plugs into a slot on the motherboard between the AGP slot and the back panel of the computer.

On newer displays lacking ADC, Apple still uses a single "ganged cable" that connects the separate signal cables to each other so they cannot tangle. This cable, however, employs standard DVI, power, USB and FireWire connectors, avoiding the problems of its predecessor.

ee also

* Apple Displays
* List of display interfaces

External links

* [http://developer.apple.com/documentation/Hardware/Developer_Notes/Macintosh_CPUs-G4/PowerMacG4_16Jan01/3Input-Output/Apple_Display_Connector.html The Electrical Interface for the ADC]
* [http://www.apple.com/pr/library/2000/jul/19display.html Apple Unveils All New Family of Displays to Complement Power Mac G4 Cube and Power Mac G4]