Does it sometimes seem that this whole convention is a broadcast from an earlier time, somehow intercepted and delayed by some freak event in the ionosphere? It seems that way inside Tampa too. Local taxis issue receipts with advertisements printed on the back. Most of the receipts advertise the service of a local attorney who specializes in criminal defense on DUI charges. Last night however I was handed a receipt advertising the CBS Evening News with Dan Rather, decorated with a smiling photograph of Rather as he looked in about 1982. "Experience you can trust" says the receipt, "Weeknights 6:30 Channel 10." Followed, one supposes, by M*A*S*H.