RSTS/E - Run-Time Environments

Run-Time Environments

One of the features of RSTS is the means for the execution of programs and the environment used to run them. The various environments allowed for programming in BASIC-PLUS, the enhanced BASIC Plus 2, and in more traditional programming languages such as COBOL and FORTRAN. These environments were separate from each other such that one could start a program from one environment and the system would switch to a different environment while running a different program, and then return the user to the original environment they started with. These environments were referred to as an RTS. The term for the command line interface that most of these RTS's had was called the KBM. Prior to Version 9, the systems manager needed to define which RTS the system would start under, and it had to be one that would execute compiled programs.

A Systems Manager may also install special CCL commands, which take precedence over all KBM commands (with the exception of DCL). A CCL is analogous to a shortcut to a program on a Windows system or a symbolic link on Unix-based systems. CCL's are installed as a memory-resident command either during startup, or dynamically while the system is running by a system's manager (i.e.: it is not permanent like a disk file).

When logged in, a user can "SWITCH" to any of these environments, type language statements in the BASIC-PLUS programming language, issue RUN commands to specific programs, or issue a special command called a CCL to execute a program with command options. Most RSTS systems managers generated the kernel to include the "Control-T" one line status option which could tell you what program you were running, under what RTS the program was using, how much memory the program was taking, how much it could expand to, and how much memory the RTS was using.