[jacobwcarlson]

> The biggest barrier to entry is getting a mainframe to experiment with.

Is there a barrier to emulating these systems? It's probably difficult (illegal?) to emulate the various Tandem operating systems on virtual hardware, but I'm sure there's a way.

I'd be shocked if there wasn't a turnkey AS/400 VM available.

[rollthehard6]

It's trivial to emulate old versions of z/OS, have a look at Hercules -

http://www.hercules-390.org/

Not sure about OS/400 (IBM i) emulation, but you can get accounts to play with it seems -

http://stackoverflow.com/questions/3487895/as400-emulator-or...