Since early1999 all Apple computers come with the USB bus only. Mice All that applies to the old ADB keyboards applies to the old mice as well. None of the old mice work with the new computers. These are somewhat flimsy looking cables that can go into the two USB ports on the back of all the new computers. The USB concept is veryflexible and it does not make anydifference where things are pluggedin or in which order.
Extension cables are OK, too.
If you are printingto a department printer via the network,thereis no need to read this paragraph. But before you invest in any of these adaptors you should consider takingthe tax write-off for the old printer and donating it to Goodwill and buyinga new USB printer. This may bethe cheaper and less painful solution in the long run.