In my past "life", I did a lot of work on Mainframes for large companies.
I've noticed that there are emulators now for running a mainframe style computer.
Plus, IBM is offering Free COBOL/JCL classes which I am taking.
And there are a number of COBOL compilers for the PC including gnuCobol.
This will be a collection of tutorials to re-create that environment and how to create and run applications for the Mainframe.