>So items 1 and 4 are courses which you need to sign up for and get everything including instruction. That fails to qualify as "on their own".
Attending a course on your Own.
>Item 2
No it's a MVS distribution (a full blown Operating System) with all the compilers 99% the same as a "modern" z/os
>Item 3
That's the S/390 emulator.
>Would you hire someone to work on a mainframe who'd never used a real system before?
Most Mainframe-Programmer where never near the Hardware anyway...so YES i would do that absolutely (you don't do Hardware near programming in Mainframes, an emulator is perfectly fine), same as a Dev who programs in a VirtualBox, no difference.
If you want to learn how to use it, and MUCH more:
Attending a course on your Own.
>Item 2
No it's a MVS distribution (a full blown Operating System) with all the compilers 99% the same as a "modern" z/os
>Item 3
That's the S/390 emulator.
>Would you hire someone to work on a mainframe who'd never used a real system before?
Most Mainframe-Programmer where never near the Hardware anyway...so YES i would do that absolutely (you don't do Hardware near programming in Mainframes, an emulator is perfectly fine), same as a Dev who programs in a VirtualBox, no difference.
If you want to learn how to use it, and MUCH more:
https://www.youtube.com/channel/UCR1ajTWGiUtiAv8X-hpBY7w
https://github.com/moshix
>Compare that to e.g. Java.
You can do exactly the same with MVS, all the compilers (and more as z/os brings with) are in it.