Besides SCSI and now usb there only two internal drive types to go with. You would either slave one ide to another or place on the secondary ide channel for EIDE transfers between drives there. Or you can simply set up a second sata drive as the second master and not as two in an array to see that additional logical drive added. It depends on what type of drive you are referring to there.
I thought more about it, and I want to make my 200gb hdd my main drive, and my 500 as my storage.
Is there anyway that I can have my 500gb drive always plugged in and recognized, but make sure it doesnt get corrupted? Like with a virus or something?
Your plan to OS the 200gb means any virus effects that drive before going to the 500gb as a rulle. It's when you copy/move files from one drive to the next that you can also move any virus/trojan there too. You should always have some good antivirus/antispyware/adware tools installed. By sweeping the OS and anything downloaded for bugs you prevent spreading anything found.