move mac operating system from one hard drive to another

I have a G3 tower...I don't know much about it or computers, so bare with me! One of the hard drives installed has mac os 10.3 on it, and the other (the bigger, start up drive) only has 10.1 on it. Is there any way to transfer the 10.3 operating system from the other hard drive to the main start up drive?
help? suggestions?

Use a program such as SuperDuper or CarbonCopyCloner. You will then have to change jumper settings making the larger drive as master and the smaller as slave, or pop it in an external case using firewire connection, if the G3 has it.

PowerPC computers can boot from an external drive weith firewire but not with USB or USB2.

awesome, thank you. i will download one of those programs and try that. what are jumper settings and how do you change them?

Check the brand of your hard drive/s and go to the manufacturers web site and get details of the jumper settings. They are little white clips that go in certain positions on the rear of the drives and dictate which drive is master and which is slave.

For example if they are both Seagate brand, master would have the blocks on positions 8 and 7, slave left blank as is shown in this link:-

http://www.seagate.com/images/support/en/us/u5_family_1.gif

new problem!
i want to download carboncopycloner or whatever its called, but i now cannot change my startup drive. i click on startup disk and they are both grayed out, with no option to click the little lock and make changes. what now??