An interface for BAK PX219.2 simulators

This note explains the operation of an interface connecting two BAK PX219.2 radar simulators to a digital computer. The simulators are able to be controlled, either manually by means of the selector switches on the indicator panel, or remotely by a computer capable of transmitting a 16 bit parallel word; a PDP-11 computer has been used for that purpose. The interface uses a Binary/BCD convertor because the simulators have been designed in such a way as to only interpret BCD words. It also includes different decoder circuits so that the command words may be interpreted in the correct form and that the data words may be routed to the correct register. Two circuits allow the interruption of the program presently executing in the computer if the simulator being addressed is in manual control or if the target pulse reaches the end of the cycle.