Apple ColorSync Display - Manual (Page 23)

Using more than one monitor
If your computer has expansion slots, you can use your monitor with one or
more additional monitors connected to your computer. You may need a video
card for each additional monitor you are using. See the manual that came with
your computer for more information.
If your Mac OS–based computer has one ADB port, you can still connect two
ColorSync monitors. You’ll need a special cable to split the ADB connector
cable into two parts.
IMPORTANT Make sure you use an Apple shielded connector cable. Most third-
party ADB splitter cables are not shielded and will not work properly with
your ColorSync monitor. (You may experience more radio interference with
an unshielded connector cable.)
Shielded connector
cable (Apple part
number M5556LL/A)
Monitor cable
(includes monitor
connector and
ADB connector)
Monitor cable
(includes monitor
connector and
ADB connector)
15 Setting Up Your Monitor