Select fire multiple drill string tester

A system is provided for selectively perforating multiple zones in a well either simultaneously, or in series, having isolation barriers, or packers, located between the perforating multiple zones, without moving the system with respect to the well. The system includes a tubing string which carries at least a first and a second perforating gun. At least a first and a second pressure actuated firing head are associated with the first and second perforating guns, respectively. A first and second packer for isolating the perforating guns from each other. A source of actuating fluid pressure for the firing head is provided, which may be the bore of the tubing string. A first selective communication device is provided for isolating the second firing head from the source of actuating fluid pressure until after the first perforating gun has been fired, and for then communicating the second firing head with the source of actuating fluid pressure in response to firing of the first perforating gun.