Hacker food = McDonald's. Yup.
I began by cutting off the ADC plug from the single wire the came out the back of the monitor and then proceeded to strip off the rubber sheath, cut off shields, and strip the internal cables. The actual cables were 26-gauge wires -- they were very thin and looked very fragile! I used a magnifying glass to help peel off the shielding. Some of the internal wires were grouped and additionally shielded; I exposed them at a shorter length to prevent cable confusion (there were multiple cables of the same color). I repeated the process for the DVI cable: first cutting it in half, then stripping the wires, and finally stripping the wires which were enclosed in a further layer of shielding. Stripping all the cables took a good hour and a half.
The next item in our agenda was to find out which wires corresponded to which pins on the DVI wire fragment. I was not quite sure what to do initially, but a MITER gave me the following tip: Apparently the ohmmeter has the nice property of displaying some odd (i.e. zero) resistance when the positive and negative leads are connected without resistance. I tested all the pins and all the wires and constructed the following charts (note: these colors may be different for your DVI cable!):
Main correspondence table
|ADC color||DVI Pin & Color (if none, function)|
|2x thick red||+25V|
|2x thick black||Gnd|
|very thin dark brown||C5|
|very thin orange||LED|
|light blue||7 yellow (single)|
|yellow||6 white (single)|
|green (twisted w/ white)||USB D+|
|white (twisted w/green)||USB D-|
|black (near USB Data)||USB return|
|light brown (t. w/ white)||24 white (white, blue)|
|white (t. w/ light brown)||23 blue (white, blue)|
|white (t. w/ orange)||2 red (red, pink)|
|orange (t. w/ white)||1 pink (red, pink)|
|pink (t. w/ white)||9 brown (yellow, brown)|
|white (t. w/ pink)||10 yellow (yellow, brown)|
|white (t. w/ black)||18 green (green, black)|
|black (t. w/ white)||17 black (green, black)|
t. = twisted
(color1, color2) = color1 is in the same shielded group as color2
Other Pins <=> Colors on the DVI fragment
|11||naked w/ yellow, brown|
|16||light brown (single)|
|14||dark brown (single)|
|3||naked (red, pink)|
|22||naked (blue, white)|
|19||naked (green, black)|
single = not in a shielded group
Male DVI-D (single link) pin numbers:
The --- pins represent unused pins; these pins are for dual link connections only.
I was left waiting for quite a bit because I didn't know how to solder and one of the MITERs who graciously volunteered to teach me, Dane, was busy with his project. After he was done, he soldered one of the wires on the monitor end with the corresponding wire on the DVI cable fragment while I watched from the side. Then he placed a heatshrink over the freshly soldered wire and blew it with a heat gun to prevent the conjoined wire from shorting the other wires. I then sat down for what seemed to be an hour and concentrated on soldering all the pairwise wires. The end product was a great big mess; Charles Guan, the MITERS god, felt sick to his stomach just by looking at it! Everyone doubted that my hack would work, but I had a sliver of hope that my first real electronics project would succeed.
After I was finished, I showed Dane the end result. He suggested that I should solder the shields (the naked wires in the shielded groups), too. I finished soldering rather quickly, heatshrinked them, and reported back to Dane. We then connected the monitor to the lab power supply, dialed it to the Apple-specified 25V, and connected the alligator clips to the red and black wires on the monitor. Dane touched the capacitative power button, which pulsed at the touch. I connected the monitor to my laptop, went into System Preferences, and hit `Detect Displays.' The monitor then came to life in mirror mode!! My five hours of hard work paid off!
Mess of cables
USB does not work. I'll get that working this week. [EDIT] A friend suggested that the monitor might internally make the +5V required for usb, so I'll have to test it this week at MITERS since I don't have the power supply in my dorm.USB does work -- see the follow-up.
- Hot-plug display detection doesn't work. I'll get that working this week.
- I will consider making a breakout box instead of hacking the monitor cable. One of these adapters costs a whopping $99 from Apple!
- The monitor runs fine on 24V and draws slightly more than 1A -- no need for 25V. I have already ordered a 24V 1.5A regulated power supply from ebay.
EDIT: Here is a followup of the hack: http://doesntexistat.blogspot.com/2010/11/apple-display-hack-followup.html
EDIT: Here it is in action: lame dual display and insanely excellent triple display