Software
The earliest operating system for the lower 3000 series was called RTS OS. However it was quickly replaced with MSOS (Mass Storage OS). The premier operating system for the CDC 3300 and CDC 3500 was called MASTER. MASTER was interrupt-driven, supported large memory, multi-tasking.
An operating system called REAL-TIME SCOPE existed for both lower- and upper-3000 systems. A disk-based version of SCOPE was eventually made available for the upper-3000 systems.
FORTRAN, COBOL, and ALGOL were available. The assembly language was called COMPASS. These were available from CDC.
An APL system for the upper 3000 series computers was developed at the University of Massachusetts Amherst. This system was made available to other users of the upper 3000 series.
Read more about this topic: CDC 3000