FOS Instrument Science Report CAL/FOS-119 "The Faint Object Spectograph Binary Search Target Acquisition Simulator BS4" by I.N. Evans Abstract excerpted from the report: The Faint Object Spectograph binary search target acquisition simulator is described. The operation and limitations of the simulator are discussed. Examples are presented demonstrating how the simulator may be user to evaluate the performance of the NSSC-1 FOS binary search target acquisition processor and perform casual analysis of failed binary search target acquistions. For more information, please contact the above authors.