To provide an operating system for a programmable controller of an electronically controlled hydraulic system.

The programmable controller for operating a machine such as one having a hydraulic system includes a memory that stores a plurality of software function routines. The memory contains a first data file with address pointers to the function routines where the address pointers are listed in the order that the function routines are executed. A second data file has a separate record associated with each of the address pointers and each record identifies data variables required by the corresponding function routine. A third data file contains information about each of the variables. A code sequencer accesses the first data file and directs the execution of the function routine in the order designated by the pointers. Since each function routine conducts executions, a record in the second data file is used to access the required variable information.