Combined Audio/Modem Codec (often referred to or abbreviated as AMC ‘97 or just AMC)ġ. Modem Codec (often referred to or abbreviated as MC ‘97 or just MC) Audio Codec (often referred to or abbreviated as AC ‘97 or just AC) Before installation, please make sure that you're not already running a newer version of the driver. We highly recommend using this package only for the hardware and software that meets producer's requests. If you already installed a previous version of this driver, we recommend upgrading to the last version, so you can enjoy newly added functionalities or fix bugs from older versions. This driver package provides the necessary installation files of Realtek AC97 Audio Driver 6.