One of the main ways that mainframe computers provide for interactive programs is via CICS (pronounced “kicks”). This reference page lists all of the common commands that you are likely to need to use in writing a CICS program including all of the parameters that can be specified with these commands.
CICS commands

I spent over twenty years programming mainframe computers using either Cobol or Pl/1 (depending on where I was working at the time). As a result, when I set up my computer help site,, a large section of the site was dedicated to answering mainframe questions.
With the outsourcing of most of the mainframe programming jobs to [...]