Apple Power Macintosh 5200/75 LC - Manual (Page 68)

If a blinking question mark appears, or if the computer starts up from your
hard disk: You did not insert the CD-ROM disc quickly enough for the
computer to recognize it as a startup disk. Follow these steps:
1 Shut down your computer.
The CD-ROM disc will remain in the CD-ROM drive.
2 Turn the computer on.
3 Immediately press the C key on the keyboard.
Continue to hold down the key until you see the “Welcome to Macintosh”
message.
Starting up from a floppy disk
To initialize, test, or repair a hard disk, or to install system software on a
hard disk, you need to start up your computer from another disk. If you don’t
have a built-in CD-ROM drive, you can start up the computer using either the
Disk Tools or Install Me First floppy disk that came with your computer.
To start up your computer using a floppy disk, follow these steps:
1 Shut down your computer.
2 Insert the floppy disk into the disk drive.
If you want to initialize, test, or repair your hard disk, use the Disk Tools disk
to start up your computer. If you want to install system software, use the
Install Me First disk.
3 Turn on the computer.
61 Troubleshooting