Apple Macintosh LC 630 DOS - Manual (Page 125)

When I try to switch to DOS, my screen is blank or has no synchronization.
If the monitor has never worked in DOS, it is most likely not able to
synchronize properly to the DOS video signal. Refer to the information in the
Technical Information booklet on monitor specifications and video modes, and
check with your monitor vendor to see if your monitor conforms to these
specifications.
If your monitor was working previously, verify that its type is selected in the
Display pop-up menu of the PC Setup control panel.
If its type doesn’t show, use the Display pop-up menu to select the correct
type. Restart the computer and, immediately after the chime sounds, hold
down the x-Option-P-R keys. When you hear another chime, release the keys.
Then open the PC Setup control panel again. You’ll get a message that PC
Setup is not properly installed. This is normal. Verify the settings, and restart
the computer again.
The Macintosh “hangs” or freezes during startup.
If the Mac OS is sharing 16 MB or more of memory with the PC
environment, and Disklight of Norton Utilities 3.1.1 is installed, the computer
will freeze during startup. This does not occur with 8 MB or less shared
memory. Restart the Macintosh using one of the techniques described in
“Start Over” in the section “When You Run Into Trouble” in Chapter 7. Open
the PC Setup control panel and change the shared memory setting to 8 MB
or less.
The DOS-compatibility software doesn’t seem to be installed.
Open the Control Panels folder and look for the PC Setup control panel. If
you find it, the DOS-compatibility software is installed. If not, or if you find
it but it doesn’t work, there may be a problem with the software. Reinstall the
software according to the instructions in “Reinstalling the DOS-compatibility
Software,” later in this chapter.
If you do find the PC Setup control panel, open it. If drive C is mapped to a
drive container, a drive container has been created. If drive C is not mapped
to a drive container, follow the instructions in “Creating a Drive Container”
in the section “Reinstalling the DOS-Compatibility Software” later in this
chapter.
114 Chapter 8