Phasing ALMA with the 64-antenna correlator

The main characteristics of the ALMA 64-antenna correlator and its status are very briefly presented. It is recalled that the basic elements required to phase up the ALMA array, and thus enhance the ALMA science objectives, have been included in the correlator original design. We give an overview of the new phasing interface card which needs to be added to the 64-antenna correlator to implement the VLBI mode in ALMA. Finally, we briefly describe the test fixture which is planned to validate in the laboratory the new phasing card and the VLBI mode without disturbing ALMA current operation.