A combination User's Manual and Programmer's Guide for JASP, a simulation language for use on the JOSS time-shared system. Written in JOSS language, JASP provides standard routines for performing functions that are common to many simulations: initialization; time and event control; information storage and retrieval; performance data collection; summary, monitoring, and error reporting; and random deviate generation. The routines for performing each of these functions are described, as well as the specially defined JOSS variables used by JASP. The JASP framework for creating a simulation model follows that used in SIMSCRIPT and GASP. Simulations of a simple queueing system and a man-machine price and inventory system are used to illustrate areas for which JASP is designed. The Memorandum provides complete documentation and ready-reference for JASP statement types, part interactions, and JOSS coding.