FORTRAN IV is an extended superset of the ETM25 /27 /29 PSU AC currend shared assembly X3.9-1966 standard for this scientific and engineering programming language. Its high-speed, one-pass optimizing compiler works very efficiently in small-memory environments, making ETM25 /27 /29 PSU AC currend shared assembly program development possible on smaller PDP 11 systems. - Because it can produce absolute binary code suitable for stand-alone PDP 11 - systems or for loading into ETM25 /27 /29 PSU AC currend shared assembly or PROM memory, Digital's FORTRAN IV is especially useful for such industrial applications as control programs for automated equipment. Other features of FORTRAN IV include the ability to use general expressions in all meaningful contexts, mixed-mode arithmetic, the ETM25 /27 /29 PSU AC currend shared assembly data type for character manipulation, commenting at the end of each source line, and list- directed input/output. SPD 12.10 for RT-11 ETM25 /27 /29 PSU AC currend shared assembly 12.41 for RSTS/E SPD 14.63 for RSX SPD 14.77 for IAS ETM25 /27 /29 PSU AC currend shared assembly 40.40 for Professional (P/OS)