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It's a fun experience to install MVS 3.8j (apparently 40 years old by now), using the Hyperion fork, to get a taste of how utterly different mainframe computing
by anyfoo 5y ago
It's a fun experience to install MVS 3.8j (apparently 40 years old by now), using the Hyperion fork, to get a taste of how utterly different mainframe computing was (and still is).
If you've never dealt with mainframes, which is extremely likely after all, you will be massively taken aback about how different everything is. A lot of the most fundamental terms you are used to, like "file" or "directory", simply don't exist. Some have equivalents with other names, but even if they do they're often so different that you barely recognize them at all... It's like finding a computer on an alien planet.
Interestingly, the later "midrange" AS/400 (or maybe also its predecessor System/36 which I don't know about) is also completely different from mainstream computing, but in something that I'd describe as the opposite way of how MVS is different.
While MVS lets you feel the bare metal at every turn (making such simple things as using the closest thing to a file, a "dataset", sometimes rather bizarre), AS/400 does the opposite and abstracts everything away. Going as far as having a 128bit unified address space, which addresses both RAM and hard disk storage and everything in between...
- jhgb 5y ago> If you've never dealt with mainframes, which is extremely likely after all, you will be massively taken aback about how different everything is. Funnily enough my alma mater recently made Introduction to Mainframes a mandatory subject for a software engineering course. So if you can't use z/OS on a (very) basic level, you can't graduate. :)
- Spooky23 5y agoAS/400 is an interesting system. When IBM stopped supporting circa 1999 25 MHz PowerPC system at a friends company in 2010, I learned a bit about it in getting rid of it. Other than CEs replacing hard disks a few times, and an Ethernet upgrade, it was undisturbed by anyone other than the end users. The server had restarted ~20 times, by power outages. Crazy stuff.
- smackeyacky 5y agoThis machine at my desk is already emulating a Sparcstation 5, a Mac Pro and a Windows 2019 machine. I might give this a crack just so I have an excuse to try to get one of the 3270 terminal emulators running. Like x3270 or one of those things that used to float around. I assume you need to emulate a terminal concentrator somehow along with the mainframe itself?
- wsh 5y agoYou only have to provide a controller, as this person did, if you want to use a real terminal: https://ajk.me/building-an-ibm-3270-terminal-controller https://ajk.me/building-an-ibm-3270-terminal-controller Otherwise, a TN3270 client program such as x3270 is enough: Hercules makes TN3270 clients appear to the mainframe operating system as though they were display stations connected to a channel-attached establishment controller. If you don’t want to install an X11 server, by the way, you can use the c3270 program that comes with the x3270 package.
- smackeyacky 5y agoOk cool. Will go do some installing.
- nix23 5y agoExtract and run MVS 3.8j TK4- [1] on Hyperion [2] is a bit...hmm less time consuming then installing a barebone MVS, plus more tools, games, compilers...and basic tcp ;) [1] http://wotho.ethz.ch/tk4-/ http://wotho.ethz.ch/tk4-/ [2] https://github.com/SDL-Hercules-390/hyperion https://github.com/SDL-Hercules-390/hyperion And a pretty good youtube channel "mostly" dedicated to MVS and other mainframe os's https://www.youtube.com/channel/UCR1ajTWGiUtiAv8X-hpBY7w https://www.youtube.com/channel/UCR1ajTWGiUtiAv8X-hpBY7w
- anyfoo 5y agoTrue, but you learn much more about the system installing yourself, and if like me you did not have any experience with mainframes... I think I'd have been utterly, utterly lost without that installing experience.