DIY ADC Adapter
It’s been a while since I added a blog entry, but this is worth it. This time I am building a DVI to ADC adapter so I can connect an old Apple Cinema Display to a PC.
The Backstory:
The PR department at the college I work for was going through some old stuff. They came across some Mac equipment they no longer wanted and asked my office, the Help Desk, to dispose of it properly. What came back were some Apple video cables and one 20″ Apple Cinema Display. It wasn’t the aluminum version, but the older white one that looked like an easel. Of course, this display couldn’t be connected to any regular computer because it used an ADC connector. Apple specially engineered the ADC connector so that power, video, and USB were carried along a single cable. While this was great for reducing the amount of cabling you had, it also meant you had to have either a PowerMac with a compatible video card or a DVI to ADC adapter. That originally cost an $130. Oh, don’t forget your computer had to have a DVI.
The Idea:
If you fast forward to today you can buy a DVI to ADC adapter for $75 from Amazon.com. That would be the quick solution for connecting the monitor to a computer, but I have an idea: why not build my own? The ADC standard is basically the same as DVI with extra wires for power and USB ports. The pinout on the connectors between DVI and ADC are a little different, but shouldn’t be too hard to over come.
The Research:
Searching the Internet revealed some good information. Most of what I found discussed building a VGA to ADC adapter for the older CRT Apple monitors, but nobody had instructions for building the DVI version for the LCD monitor. Regardless most people recommended looking at the Apple development library to see the ADC pinout and spec (1). I also found a few more important articles from Apple. The Apple DVI to ADC Adapter: Compatibility Table (2) has a note that says the monitor must be plugged up to USB to have brightness, power, and sleep functions. Another page, the Apple Cinema Display Tech Specs, (3) let me know the power requirements. From all of the research I did, here was a table showing what pins would need to be connected.
| ADC | DVI | Use |
|---|---|---|
| Pin 1 | 25 V Supply | |
| Pin 2 | 25 V Supply | |
| Pin 3 | ||
| Pin 4 | Pin 17 | TMDS data 0− |
| Pin 5 | Pin 18 | TMDS data 0+ |
| Pin 6 | Pin 19 | TMDS data 0/5 shield |
| Pin 7 | ||
| Pin 8 | ||
| Pin 9 | Pin 7 | DDC data |
| Pin 10 | Pin 8 | Analog vertical sync |
| Pin 11 | Pin 15 | 25 V Return |
| Pin 12 | 25 V Return | |
| Pin 13 | ||
| Pin 14 | Pin 9 | TMDS data 1− |
| Pin 15 | Pin 10 | TMDS data 1+ |
| Pin 16 | Pin 11 | TMDS data 1/3 shield |
| Pin 17 | ||
| Pin 18 | ||
| Pin 19 | Pin 6 | DDC clock |
| Pin 20 | Pin 22 | TMDS clock shield |
| Pin 21 | USB Data+ | |
| Pin 22 | USB Data- | |
| Pin 23 | USB Return | |
| Pin 24 | Pin 1 | TMDS data 2− |
| Pin 25 | Pin 2 | TMDS data 2+ |
| Pin 26 | Pin 3 | TMDS data 2/4 shield |
| Pin 27 | ||
| Pin 28 | ||
| Pin 29 | Pin 23 | TMDS clock+ |
| Pin 30 | Pin 24 | TMDS clock− |
| C5 | C5 | Ground |
Included in the pile of cables that came back with the monitor I found an ADC to DVI cable. This cable was made by Belkin and was designed so you could connect a regular DVI equipped monitor to a PowerMac with an ADC connector on the video card. It did the same thing I wanted, just in the opposite direction. Still, the ADC to DVI cable allowed me do a signal test between contacts and confirm the my chart was correct.
The Parts:
To build the adapter here is what I purchased.
1x ADC connector, $3.00 (4)
1x DVI connector, $4.84 (5)
1x USB connector, $1.12 (6)
1x Power connector, $0.63 (7)
1x Protoboard, $16.85 (8)
1x 90W 24V PSU, $8.76 (9)
Other things I needed were a solder iron with very fine tip, solder, solder flux, a steady hand, and a good bit of luck.
Note: I couldn’t use a regular protoboard from Radioshack because of the hole spacing. The ADC and DVI connectors are based on the SMD (surface mount device) standard so the pins are spaced at 1.9mm. A standard hobby board has holes spaced at 2.58mm or 0.01″. The board listed above is the only one I found to be punched at 2mm and have solder pads.
The Build:
Putting everything together was tedious, but fairly straightforward. I started by installing all of the connectors onto the protoboard. This took some work because the pints were spaced at 1.9mm and the holes at 2.0mm. After a little but of wiggling everything lined up.
Now for the hard part. I had to carefully solder a wire to each of the desired pins. This was made especially difficult because of the some wires cover pins I needed access later. The solution was to solder wires on the pins closest to the middle of the board and then work my way out, attaching the wires on to the other connector when necessary.
The beginning: 
The result: 
With the hard part of the project the next step was to protect it from damage using a case. What project would be complete without an Altoids case. Lucky enough I had an Altoids tin sitting around for a future project. Lucky me. Using a Dremel and cutoff wheel I cut holes in the side of the case for the ADC, DVI, USB, and power connectors.
Here you can see how everything looks installed.
The Payoff:
After checking all of the input/outputs based on the chart above the only thing left was to plug in the cables. I was honestly surprised not to find any smoke rolling from the case. What’s more surprising was to see my computer detect the monitor and a picture actually show up. The screen was bright, responsive, and the colors looked good. I also connected the monitor to my PowerMac and was able to control the brightness of the backlight; something not possible from Windows 7 64-bit.
And there you have it. One working home made DVI to ADC adapter. Not bad for an amateur electronics geek.
I case your were wondering about the loose wires and red toolbox, the PSU I ordered hadn’t arrived yet so I had to use my DIY project PSU to power the monitor. It really wasn’t designed to output enough amps for the monitor, but worked for testing.
Update:
Here is a wiring diagram of the adapter. I just wish it was as easy to physically run the wires as it was in the schematic. 
Источник
Question: Q: DVI to ADC adapter
This one is a little tricky. i have a 20″ Apple Display with an ADC connection. my friend who owns an older G4 believeed to have a DVI-D and VGA connection wants to buy it but we’re wondering if there is any way to hook it up. I have an Apple DVI to ADC adapter but I don’t know if it works for just DVI-I or what. he lives a few hours away so we can’t just try it out. if anybody knows anything please let me know.
PowerMac G5, Mac OS X (10.4.9)
Posted on Oct 1, 2007 3:30 PM
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The adapter to connect an ADC display to DVI-I or DVI-I is
The cheap adapters are for connecting a DVI display to a computer with ADC.
Before buying the adapter, find out what graphics board is in the G4. The older G4 DVI graphics boards would not work with a 20″ display, even with the right adapter.
Oct 1, 2007 5:19 PM
Oct 1, 2007 5:26 PM
Ok, here is what I know about the computer.
G4 400mhz PowerPC
Chipset Model: ATY,Rage128Pro
Type: Display
Bus: AGP
Slot: SLOT-A
VRAM (Total): 16 MB
Vendor: ATI (0x1002)
Device ID: 0x5046
Revision ID: 0x0000
ROM Revision: 113-63001-108
Displays:
900U:
Resolution: 1152 x 870 @ 75 Hz
Depth: 32-bit Color
Core Image: Not Supported
Main Display: Yes
Mirror: Off
Online: Yes
Quartz Extreme: Not Supported
Oct 1, 2007 7:44 PM
Oct 1, 2007 8:14 PM
Oct 1, 2007 8:41 PM
I found some luck with a 9600 Pro graphics card running an old 15 inch Studio Display. There’s a strange mouse artifact created when scrolling, but otherwise it seems to work pretty well. I used Dr. Bott’s DVIator to make the connection and the USB ports on the screen work just fine.
The only reason I mention this is that the 9600 pro is a cheap alternative that might still work well enough.
Источник
Question: Q: DVI to ADC adapter options
$15). It will be the only monitor on this computer. Thanks!
Mac Mini 1.66 dual core, Mac OS X (10.3.9)
Posted on Feb 16, 2007 9:23 AM
Helpful answers
There are alternatives to the Apple item, but they are typically roughly the same price — see http://www.drbott.com/prod/db.lasso?code=0111-DVAD for example, and http://www.ramelectronics.net/html/DVI_ADC-converter.html#dviadc which is more expensive still!
The reason they are more expensive than the other types of adaptor is that they do more than simply reroute pins. And of course the market for them is relatively small, so you don’t get the benefits of the economy of scale you do with other devices.
Feb 16, 2007 9:38 AM
Feb 19, 2007 5:09 AM
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There are alternatives to the Apple item, but they are typically roughly the same price — see http://www.drbott.com/prod/db.lasso?code=0111-DVAD for example, and http://www.ramelectronics.net/html/DVI_ADC-converter.html#dviadc which is more expensive still!
The reason they are more expensive than the other types of adaptor is that they do more than simply reroute pins. And of course the market for them is relatively small, so you don’t get the benefits of the economy of scale you do with other devices.
Feb 16, 2007 9:38 AM
Feb 18, 2007 6:17 AM
Feb 19, 2007 5:09 AM
I’m with Andy on this suggestion.
If you look for Dell’s periodic sales, you can get really good prices on Dell LCD monitors, which have excellent specs, more adjustability than Apple monitors, and which come with 3-year warranties.
I love my Dell 17″.
techbargains dot com is good place to look for such deals.
Feb 19, 2007 5:24 AM
Feb 20, 2007 6:56 AM
Feb 20, 2007 7:05 AM
Additionally of course a new DVI display would likely have faster response times, better luminance and contrast and wider viewing angle than the older technology Apple display, thus be more suited to such tasks as gaming and video where the older displays were typically a little blurry or dull.
I also think the range of height and angle adjustments on most new displays are rather better than the Apple Studio LCD, so they’re often easier to set up for a more comfortable seating position.
Feb 20, 2007 7:25 AM
Feb 20, 2007 11:51 AM
Question: Q: DVI to ADC adapter options More Less
Источник
Разъем Apple Display — Apple Display Connector
Компании Apple Display Connector ( ADC ) является собственной модификацией DVI разъема , который сочетает в себе аналоговые и цифровые видеосигналы, USB , и власть все в одном кабеле . Он использовался в более поздних версиях Apple Studio Display , включая последнюю 17- дюймовую модель CRT и большинство версий широкоэкранного Apple Cinema Display , после чего Apple приняла стандартные разъемы DVI на более поздних моделях.
Впервые реализованный в Power Mac G4 и G4 Cube в июле 2000 года , ADC исчез с дисплеев в июне 2004 года, когда Apple представила алюминиевый корпус Apple Cinema размером 20 дюймов (51 см), 23 дюйма (58 см) и 30 дюймов (76 см). Дисплеи с отдельными разъемами DVI , USB и FireWire , а также с собственными источниками питания. Порт ADC все еще был включен в Power Mac G5 до апреля 2005 года, когда новые модели означали, что единственным оставшимся продуктом Apple с интерфейсом ADC был один процессор. Power Mac G5 представлен в октябре 2004 года. Выпуск этого однопроцессорного Power Mac G5 был прекращен вскоре после того, как в июне 2005 года.
СОДЕРЖАНИЕ
Совместимость
Разъем Apple Display Connector физически несовместим со стандартным разъемом DVI. Адаптер Apple DVI to ADC, который на момент запуска стоил 149 долларов США, но в 2002 году был доступен за 99 долларов США, принимает USB- и DVI-соединения от компьютера вместе с питанием и объединяет их в соединение ADC, позволяя использовать мониторы ADC с Машины на базе DVI.
Первоначальная реализация ADC на некоторых моделях Power Mac G4 предполагала удаление разъемов DVI с этих компьютеров. Это изменение потребовало использования пассивного адаптера ADC-DVI для использования монитора DVI.
АЦП обеспечивает мощность до 100 Вт, что недостаточно для работы большинства ЭЛТ 19 дюймов (48 см) или больше, широко доступных во время дебюта ADC, а также он не может работать с современными плоскими панелями, продаваемыми для домашних развлечений (многие из которых поддерживают DVI или VGA-соединения) без адаптера. Ограничение мощности было важным фактором для отказа Apple от ADC при выпуске 30-дюймового (76 см) дисплея Apple Cinema HD.
На более новых дисплеях на базе DVI без ADC Apple по-прежнему выбирала один «соединенный кабель », который соединяет отдельные сигнальные кабели друг с другом, чтобы они не запутались. Однако в таких кабелях используются стандартные разъемы DVI, питания, USB и FireWire, что позволяет избежать недостатков АЦП. Начиная с 2008 года Apple начала отходить от DVI, приняв все более распространенный стандарт сигнализации DisplayPort и разработав собственный разъем Mini DisplayPort , начиная с первых кинотеатральных дисплеев со светодиодной подсветкой. С 2013 года Apple больше не использует интерфейс на основе DVI ни для одного из своих дисплеев.
Apple больше не поддерживает адаптеры и мониторы ADC.
Пин 3 и 11
Питание на порт ADC подается через дополнительный пальчиковый разъем на видеокарте, который вставляется в слот на материнской плате между слотом AGP и задней панелью компьютера; на компьютерах Mac G4 некоторая мощность также передается через контакты 3 и 11 AGP. Когда был введен ADC, контакты 3 и 11 AGP не были назначены. В AGP 8x контакты 3 и 11 были назначены, поэтому G4 напрямую не совместимы с AGP 8x. Компьютеры Mac G5 получают все питание через разъем для пальцев и, следовательно, совместимы с 8x. Чтобы использовать карту AGP 8x в G4, контакты 3 и 11 должны быть каким-то образом отключены; это можно сделать, наложив ленту на проводящую часть штифта, разрезав дорожки на печатной плате, или, на некоторых картах, отпаяв резисторы для поверхностного монтажа.
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