[dominicjj]

You can! You need to install the Hercules mainframe emulator and the freely available MVS 3.8 on top of it. There are compilers for COBOL, Fortran, PL/1 and assembly available. The go to guy on YouTube for getting all this working is moshix:

https://www.youtube.com/c/moshix

[7thaccount]

How close is it to the real deal in emulating something like a modern mainframe?

[dominicjj]

Very close to the real deal only when emulating a 370 from the 80s. zOS is a different beast though even though it shares a lot of the asm underneath. But there is no way to run zOS for yourself without a license from IBM or access to a real z-series somehow.

[7thaccount]

Kinda what I figured. Th whole concept of a mainframe is pretty neat in that you can go through the 1000 page manual and have an idea about all that is possible, instead of an infinitely changing software tool ocean. The latter is probably better overall, but it would be neat to check out the mainframe paradigm.

[trasz]

Running z/OS on Hercules is trivially easy, you just need to ignore the license. The z/OS software distribution is usually called ADCD.

[7thaccount]

Yeah, I'm only interested in using software legally, but it's a shame IBM doesn't make this available. It's not like someone is going to just port all their mainframe apps to run on this emulator right? Or is that a real concern of theirs? I figure the hardware itself is the secret sauce.

[exikyut]

I get the impression (as a vaguely interested outsider looking in from a distance and making a LOT of presumptions) that it's "just" institutional drag and "tradition". Create a culture founded upon filling in forms and ticking boxes, and "hi I can haz?" is going to produce $every_windows_error_at_once.wav, a lot of hand-wringing, and an internal processing chain that'll naturally tumbleweed itself in the general direction of the legal department. Network effects / emergent behavior. Soo, you read between the lines ("ah, it's fine, the requirement was fulfilled"), and take it from there. 𝙻𝚘𝚐𝚘𝚗 ===> _

The only reason I haven't pursued this myself is that MVS is ultimately just not objectively compelling enough, because while it's similar to what's out there today, I get the impression I'd only have to unlearn an arbitrary bunch of things once I was on the "real" system.

As an aside, I happened to stumble on a copy of "IBM and The Holocaust" a few years ago. It's a startling insight into IBM's beginnings tabulating and wrangling data on the millions of Jews "processed" throughout Germany in WW2, which turned out to be the first commoditized consumption of what would today be regarded (without a second thought) as big data.

The world has certainly moved on since that point and IBM's DNA is completely different today, but IMO the "data processing" energy still remains as an incredibly strong centerpoint, and I honestly see mainframes as a digitized realization of the punched-card concepts IBM's beginnings were founded upon. (Combined with the institutionalization aspects I hinted at in the first paragraph, this is the main reason I'm very hesitant I'd survive in what sounds like an especially rigorous environment.)

While the UI of reading a printed book hasn't yet been beaten (I'll switch to e-readers once they can pageflip instantly -.-), it's very practical to be able to virtually pick up a book and thumb through any portion. To this end, PDFs of this title seem to readily be floating around, for example (open as URL) data:text;base64,aHR0cDovL3Bvc29oLnJ1L2Jvb2svaHRtL2libS5wZGY

I will note that after reading I kinda looked askance at my ThinkPads a bit and went "wow, what a history. uhhh....". Fair warning :)

[dominicjj]

I should have said 'legally'.