MVSSERV includes programs called access method drivers (AMDs), which manage Host-to-PC communications across certain hardware connections. Specifically, the MVSSERV AMDs communicate with PCs that have Distributed Function Terminal (DFT) and Control Unit Terminal (CUT) mode attachment to the host through the IBM® 3174 or 3274 control unit. In addition, MVSSERV allows installations to write and install their own AMDs to manage other communication methods. Writing an Access Method Driver describes MVSSERV's AMD interface and special considerations for writing your own AMDs.