Out of all mainframe OSes, VM is the most approachable imo, as long as you grasp minidisks and how s390 device addressing works, it becomes just a somewhat clunky DOS. I would also suggest checking out the 2.4 VM ADCD, it is a package with basically all the interesting software, and it is out there if you look for it.

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rbanffy 5 hours ago | parent [-]

> a somewhat clunky DOS

And the Community Edition even has a handy DIR command for you.

This document has a lot of things left to add - the machines can really be a lot more interesting. So far, I haven't figured out how to connect my real printer over the network, the other machine with shared disks but no OS, and even creating a new VM for our user. I also know there are a lot of other interesting things on the base CE image that can be super cool to show a newcomer.

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coolkil 3 hours ago | parent [-]

It is a very cool operating system. I had the pleasure of configuring it (in it’s ibm z/VM form) from scratch a few years ago. However due to company politics it only ran for 2 years. If you are based anywhere in the US you could probably make a career out of it. If you are in Europe I don’t know if it is a wise choice. Not much z/VM there. If you now own a modern mainframe and want to run Linux workload for example I think you are better of using kvm. However if you need to run z/OS virtualised your only option is still z/VM

	▲	rbanffy 39 minutes ago \| parent [-]
		I have recently played with a plain VM/370 R6 and it's very bare compared to CE - not even bold in the terminal to highlight your current line in EDIT. I was thinking of adding it to my collection of Docker images, but I need to play with tape images and, perhaps, load a bunch of them into the container image so there is something to do with it that resembles modern computing.