The purpose of this report is to describe POGINOUT, a simultaneous input-output utility program for the IBM 1401 computer. The procedure is given for writing any 1401 program with simultaneous input-output. The description and procedure can be used in writing similar utility programs for 1401's used as peripheral equipment to a larger computer. The report contains comments on procedures not used in POGINOUT but which might be appropriate under slightly different conditions. Familiarity with this program aids in optimum use of the POGO executive system. The normal user will find those sections pertaining to code words and carriage control the most useful.