Firstly confirm what resolution and frequency is supported by the monitor.
Decide on a suitable resolution to apply to Solaris.
Permanent setting - both command prompt and desktop (CDE) login
===============================================================
1. shutdown to openboot prompt
# shutdown -i 0 now
2. change the resolution
ok setenv output-device screen:r800x600x75
ok reset-all
3. boot up
ok boot
4. subsequently the screen resolution will r800x600x75 for command prompt session as
well as desktop (CDE) session
Note: the "ok" is the openboot prompt and not to be typed.
Temporary setting - Desktop login only
======================================
Exit the desktop (CDE) login - from the CDE login screen,
select Options -> command line login.
From command line login, to set to 1024x768 @75Hz :-
1. check what resolution is supported on your system
# m64config -prconf
2. select a suitable res and apply with a try
# m64config -res 1024x768x75 try
3. If the try is successful, and when prompted to accept it as the new setting,
select yes
4. exit the command prompt login to resume CDE desktop login
# exit