Here's an old post from my 'Full VGA Support for Modchips!' thread that should help those who need help creating a native VGA cable for their XBOX:
NOTE: The Microsoft XBOX HD Pack w/Component-to-VGA Cable is the easiest option if you have a Sync-on-Green compatible monitor.
You have three options for building a VGA cable. First, you can build an LM1881N VGA cable (best option), this cable is compatible with ALL VGA monitors. Second, you can build a Sync-On-Green VGA cable, which is ONLY compatible with Sync-On-Green VGA monitors. Third, you can simply purchase an XBOX HD Pack, and use a Component-to-VGA adapter, but, this option is also ONLY COMPATIBLE with Sync-On-Green VGA monitors.
Here are some pictures:
LM1881N VGA Cable - (Picture taken from 360Mods.com) (Best Option)

My Finished LM1881N VGA Cable - (I built this cable myself, and it is based on the above diagram.)

Sync-On-Green VGA Cable - (Picture taken from 360Mods.com)

Microsoft XBOX HD Pack w/Component-to-VGA Cable

