A machine (46) for attaching an Insulation Displacement Connector (IDC) (10) to a cable (20) includes a fixture (76, 240) for engaging and arranging individual wires (18-18) in the cable in parallel, spaced-apart relationship. The machine also includes a press mechanism (51, 54, 101, 102)) for engaging a mandrel (12) of the IDC (10) and for pressing it against the wires (18-18) engaged by the fixture (76, 240) to seat each wire in a corresponding mandrel channel (14). The press mechanism (51, 54, 101 and 102) further functions to press the mandrel (12), with the wires (18-18) seated in the mandrel channels (14-14), against a IDC contact block (22) to engage each wire with an end (30) of a corresponding IDC contact (24) to accomplish attachment. As the wires (18-18) are pressed into the mandrel channels (14-14), a blade (106) severs the excess portion of each wire to facilitate attachment of the wires to the contacts.