1998 Acura CL Radio

My dad just gave me his Acura cause he can't drive anymore. It runs fine but he let the battery go dead alot this winter. I have a new battery in it but the problem is with the RADIO. It says to enter a code for it to work . He has AD and cannot even remember yesterday more than what the code would be. Knowing my dad he would of left it FACTORY set. Is there such a thing--Any and all help would be appreciated since I will use the car to shuttle dad around and he likes music.

take your registration and or the stereo out and write down the serial number on the back and model number and take that info along with the registration to the acura dealership and ask them to retrieve your radio code they might charge but they will know what it is sometimes the number can be found on the side of the glove box or back of it