I don't have an ADC display and don't own any Firewire devices so I had no intention of doing it to my MDD, but you raise some very good points.

I ran into a roadblock with my cable design anyway. I realized I was one +3.3V wire short so unless I wanted to involve an SATA connector in some way it wouldn't work. I ended up just directly splicing everything together for my MDD. Finally came up with enough of the various voltages (and a bunch of extras...) I needed after sacrificing the 20+4 connector, one 4 pin 12V rail, and an SATA connector.

At least everything is wired correctly, except for the +25V pin, which I just omitted.

I do wish I had gotten a slightly better quality power supply though. It was completely wired with 20 AWG wire. I much prefer, especially for 12V rails, to have them running over 18 AWG wires. They wires also weren't tinned, just bare copper.

The final configuration didn't turn out too bad for $193 USD:

Dual 1.25 GHz G4

1.25 GB of RAM

240 GB HD (2x120) Ultra ATA/100

Nvidia Geforce4 4600 TI 128 MB (DVI/ADC)

DVD-R

Airport Extreme

2.0 EDR Internal Bluetooth Module

New 2-Port USB 2.0 PCI Card

New Hacked ATX Power Supply

Leopard 10.5.8 Clean Install on HDD 1

Tiger 10.4.11 w/ Classic 9.2.2 on HDD 2