Nikon D1 Manual page 117

3 Turn the camera on. Then, holding down the mode dial lock release, turn
the mode dial to PC (PC mode).
If the camera is properly connected and Nikon Capture is running on your
computer, the letters "PC" will be displayed in the control panel on top of
the camera ("PC" is not displayed when Nikon View DX is running). Refer
to your software manual for information concerning the operations that can
be performed while the camera is connected to a computer.
If the camera is not connected to a computer, or if it is connected when
neither Nikon View DX nor Nikon Capture is installed, the camera will
function as it would in single-frame shooting or continuous shooting
modes. The only differences are that the frame advance mode (single or
continuous) is set using Custom Setting item 30, and that photographs are
not displayed on the monitor in capture-preview mode, record-and-review
mode, or in single-image playback.
4
Before disconnecting the IEEE 1394 cable from the camera, turn the
camera off. Do not turn the camera off or disconnect the camera when data
transfer is in progress.
Notes
Do not use the camera with the computer while battery power is low or the batteries
are exhausted. If the battery indicator changes to low or starts to flash while the
camera and computer are connected, wait for data transfer to terminate, then
disconnect the camera and replace the batteries or connect the EH-4 AC adapter (sold
separately).
It is recommended that the camera be powered by the EH-4 AC adapter (available
separately) when you are using the Nikon digital camera D1 with Nikon View DX .
When using an EN-4 battery pack, be aware that leaving the camera connected when
the battery is exhausted may shorten battery life. Should the battery become
exhausted, insert a fully charged spare battery without delay or disconnect the camera
from the computer. The amount of charge remaining is shown by the battery indicator
in the control panel on top of the camera.
Only photographs that conform to the Design Rule for Camera File Systems (DCF) can
be transferred from the camera to the computer in PC mode while Nikon Capture is
running on the computer.
104
Connections: Connecting to a Computer