Probably doesn't matter (although that is a genuine Hayes so it probably supports both) because a lot of those old modems were capable of "operator dial". AKA y

Probably doesn't matter (although that is a genuine Hayes so it probably supports both) because a lot of those old modems were capable of "operator dial". AKA you dial the phone manually then you tell the modem to start negiotiation. AKA ATDT is a tone dial, while ATDP is a pulse dial, or just plain ATD to start negotiation.