Ever wanted to try programming an IBM 360? Well now your little PC can simulate big iron. The simulator, Hercules, will run MVS which is apparently freely available, or it can run other mainframe software that you have licenses for. There is a pretty active user community, and the emulator’s support is broad enough that it looks like you can do real work on it. I doubt your PC will keep up with the latest multiprocessor 3090, but it is faster than your typical 70’s era 360 (although maybe not as much available DASD — maybe).

Check it out at http://www.bsp-gmbh.com/turnkey/