Thanks for this, can't wait to try it out. I discovered the Hercules emulator a while back, downloaded everything and fired it up, then discovered I had literally no idea how to do anything. It's just such a different world than the ones I'm familiar with.

Indeed, it seemed to me, back in the 1980s, that schools almost consciously refused to teach anything about IBM mainframes. My junior college had a 4331 and a Prime 650; the 4331 was used for school administration purposes and the 650 was used for coursework, and never the twain met. Networking was in its infancy and basically didn't exist on-campus, with all terminals hardwired. When I got to UIUC, almost anything interesting was being done on either on UNIX or on CDC mainframes (or the Cray that I saw but never used).

A guide like this is quite handy for an old hand at computers who finds mainframes completely alien. It's even odder that this old version of VM was open, and yet that never really gained much traction outside of diehards keeping the flame alive. I wonder what the computing world would look like today if VM had been put under a copyleft license? I also wonder if an XT/370 could run this thing natively, or if the 370 side was too slow/lacking needed features.