It is possible to upgrade a non-AV model to an AV model with the installation of the Power Macintosh AV card, the PlainTalk software, and the Audio/Visual utilities that come with the Power Macintosh CD version 2.0, which ships with all Power Macintosh models.
The PlainTalk microphone is available from finished goods or service. This provides the customer with an equivalent Power Macintosh AV configuration.
The AV configuration requires a significant amount of RAM. Apple recommends a minimum of 16 MB for best overall performance.