I have just discovered that startupmanager is not maintained anymore:
https://launchpad.net/startup-manager/+announcement/8300
Its author suggests the use of "Grub Costomizer" (not in the repository):
https://launchpad.net/grub-customizer
However, completely disabling the splash screen should be a matter of:
1) launching from a terminal (in the Accessories menu) and with the
administrator's rights ("sudo") your favorite editor (here "emacs") on
/etc/default/grub:
$ sudo emacs /etc/default/grub
2) locating the following line:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
3) removing both keywords making the line appear as follows:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
4) saving and quitting the editor
5) updating GRUB2 with the following command (again executed with
administrator's rights):
$ sudo update-grub
Tell me if that work (I have not tested but I am quite confident it will
work).
