Compaq AlphaServer 1200 User Manual page 23

The console terminal can be a serial (character cell) terminal connected to the COM1
port or a graphics monitor connected to a VGA adapter on PCI 0. If the console
terminal is connected to COM1, the entire power-up display prints. (See Section 3.2
for information about the power-up display.) If the console terminal is a VGA
monitor, console power-up messages are sent to those devices but SROM and
XSROM power-up messages are lost.
The console environment variable is set to serial when the console terminal is a
serial terminal; it is set to graphics when the console terminal is a graphics monitor.
(See Section 4.18 for information about environment variables.)
If the console environment variable is set to serial, os_type is set to unix or
openvms, and no terminal is attached to COM1, pressing a carriage return on a
graphics terminal attached to the keyboard port (after power-up testing has
completed) makes it the console device and the console prompt is sent to it.
If the console environment variable is set to graphics and no graphics monitor is
attached to the keyboard port, pressing a carriage return on a serial terminal attached
to COM1 (after power-up testing has completed) makes it the console device and the
console prompt is sent to it.
NOTE: The console prompt displays only after the entire power-up sequence is
complete. This can take up to several minutes if the memory is very large.
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