ethernet cable and time machine
IF I do not hook up my time machine/airport to the internet, can I still use it just as a back-up system? Do I do that with an internet cable? Thanks
iMac, OS X Mountain Lion (10.8.2)
Yes, and you can use either Ethernet or WIFI.
But since you have an iMac, it will be much faster, easier, and more reliable (not to mention $200 cheaper) to back up to a directly-connected external HD.