Compaq DS10L - AlphaServer - 256 MB RAM Reference Manual page 104

2.18.17 tt_allow_login
Enables or disables login to the SRM console firmware on
alternate console ports. If the environment variable console is set
to serial, the primary console device is the terminal connected
through the COM1 port. The command set tt_allow_login 1 enables
logins through either the COM2 port or a graphics monitor.
Syntax: set tt_allow_login value
where value can be:
(default) 1
Enables login through the COM2 port or a graphics monitor.
0
Disables login through the COM2 port or a graphics monitor.
2-52 DS10 / DS10L Console Reference