Originating registers (OR) are wired to the trunk link frame (TLF). In the original 5XB, a marker, once alerted to a trip condition, picks an OR by the same mechanism it uses to pick a trunk, identifies a clear path between line and OR, loads the OR with any information necessary for later processing (such as line equipment and class of service) and releases itself. The OR then receives the digits (rotary or tone), stores them in reed relay packs, and used the pretranslator to determine how many digits to receive before calling in the marker again to complete the call.