Hello World on z/OS • Hacker News Board

Re: Hello World on z/OS

#71

Post by rbanffy » Tue, Jul 31, 2018, 4:39 PM UTC

voidmain0001 wrote: post #24

nailer wrote: post #2

I demember doing virtualisation/containerisation for Linux on various platforms (including s/390 and z/VM but also VMware and Xen) at IBM. No matter what the platform was, the PMs would refer to the VM/container as an 'LPAR' (logical partition). Fun times.

Me too! I setup a couple of Linux LPAR on AS/400 - iSeries running OS/400. The distro was RedHat for PowerPC. One LPAR was for a Linux/Apache/PHP stack that used the DB2/400 database on the iSeries, and the other was to host an Oracle 8i instance. DB2/400 was a great RDBMS but there was an application requirement for an Oracle database, so the director of IT at the time said that if a DB is required then it must go o…

> it must go on the iSeries since it hosts the primary DB the company used.

Putting all the eggs in the same basket to justify the basket. That's classical pointy-haired thinking.

Re: Hello World on z/OS

#72

Post by binarycrusader » Tue, Jul 31, 2018, 4:50 PM UTC

wolfgke wrote: post #11

userbinator wrote: post #4

The reason why things are the way they are on mainframes, and how you should think intuitively, becomes a lot clearer once you realise that they are a long-evolved version of the very first mechanical punched-card processors: https://en.wikipedia.org/wiki/Unit_record_equipment In fact, I'm almost willing to bet that the foreignness of mainframes to the average developer is due to mini/microcomputers having become dom…

> Linux and DOS/Windows have far more in common with each other than mainframe OSes, despite their huge differences, because they evolved from mini/microcomputers and UNIX. Surely Linux and the Windows NT line (don't confuse the Windows 9x line, which evolved indirectly from DOS with the Windows NT line) have much more in common with each other than mainframe OSes, but Windows did not evolve from UNIX: The Windows 9x…

Solaris has event ports which are equivalent to Windows IOCP. So not all *NIX systems are deficient in that regard :)

Re: Hello World on z/OS

#73

Post by walrus01 » Tue, Jul 31, 2018, 5:16 PM UTC

rbanffy wrote: post #63

Just a shameless plug: there is very little information in the form of Stack Overflow-like things and getting started with mainframes is, as this article shows, pretty hard. I made this SE proposal that's in commitment stage (where people commit to support the community). If you know about mainframes and are willing to be part of it, you should commit too. https://area51.stackexchange.com/proposals/118484/mainframes.…

The hard part for mainframes is that unlike Linux and the BSDs, you can't acquire a bunch of 4 year old Core i5 systems for $80 each (or sometimes free) and install a bunch of different OS varieties on them to test stuff in your home office or the bedroom of a bored teenager (example: centos hosting KVM VMs, debian + xen, freebsd on bare metal, etc).

Re: Hello World on z/OS

#74

Post by nickpsecurity » Tue, Jul 31, 2018, 5:24 PM UTC

wolfgke wrote: post #11

userbinator wrote: post #4

The reason why things are the way they are on mainframes, and how you should think intuitively, becomes a lot clearer once you realise that they are a long-evolved version of the very first mechanical punched-card processors: https://en.wikipedia.org/wiki/Unit_record_equipment In fact, I'm almost willing to bet that the foreignness of mainframes to the average developer is due to mini/microcomputers having become dom…

> Linux and DOS/Windows have far more in common with each other than mainframe OSes, despite their huge differences, because they evolved from mini/microcomputers and UNIX. Surely Linux and the Windows NT line (don't confuse the Windows 9x line, which evolved indirectly from DOS with the Windows NT line) have much more in common with each other than mainframe OSes, but Windows did not evolve from UNIX: The Windows 9x…

On top of it, the Linux ecosystem has evolved in cloud space to be more like VMS with things like metering, more security restrictions, clustering, and so on. The "unnecessary" stuff that was integrated with VMS ground up got bolted onto Linux's later.

Re: Hello World on z/OS

#75

Post by rbanffy » Tue, Jul 31, 2018, 5:28 PM UTC

walrus01 wrote: post #73

rbanffy wrote: post #63

Just a shameless plug: there is very little information in the form of Stack Overflow-like things and getting started with mainframes is, as this article shows, pretty hard. I made this SE proposal that's in commitment stage (where people commit to support the community). If you know about mainframes and are willing to be part of it, you should commit too. https://area51.stackexchange.com/proposals/118484/mainframes.…

The hard part for mainframes is that unlike Linux and the BSDs, you can't acquire a bunch of 4 year old Core i5 systems for $80 each (or sometimes free) and install a bunch of different OS varieties on them to test stuff in your home office or the bedroom of a bored teenager (example: centos hosting KVM VMs, debian + xen, freebsd on bare metal, etc).

With zSeries it's a bit harder, but for the iSeries (I still count AS/400 as alien enough to be "mainframes"), you can get machines for reasonable prices. The prices drop precipitously when that hardware is dropped from the last OS release.

For Z machines, you can use Hercules as an acceptable approximation. A couple questions I posted as example are about Hercules.

Re: Hello World on z/OS

#76

Post by tolle » Tue, Jul 31, 2018, 5:40 PM UTC

bonzini wrote: post #55

Softly wrote: post #27

Missed my favourite part of learning the mainframe: where the enter key is. Return and enter and two different keys, but, on most modern systems, they perform a similar function. On z/OS Return moves down a line (similar to Tab, but ignoring all entries on the current line) and Enter actually sends to data off. Once you get used to it, it's really no different to the Linux or Windows command lines. It's certainly dat…

The ISPF editor is actually more than decent. About 20 years ago my father was writing COBOL (on both AS/400, now iSeries, and PC) using SPFPC, an MS-DOS editor inspired by ISPF. The line command/primary command mechanism is really no more quirky than vi's movement and insert modes, and it makes a lot of sense for languages like COBOL.

SEU, the built in editor on the iSeries/IBM i, is however rather shitty. It does actually do some linting, but no syntax highlighting and the 5250 interface never really got improved as much as 3270, so its 24x80 or 27x132. Granted you're supposed to use an eclipse based IDE since SEU is no longer supported, but to just look at stuff really quick. A fast editor is preferred.

But I agree, ISPF editor is rather good.

Re: Hello World on z/OS

#77

Post by tolle » Tue, Jul 31, 2018, 5:48 PM UTC

floatboth wrote: post #32

dralley wrote: post #21

Earlier quoted context omitted.

One of my older coworkers told me that IBM used to have a travelling mainframe demo in the back of a truck. As part of this demo, they would start a big computation, and then reach into the mainframe and start pulling out RAM and entire CPUs straight from the sockets, while the thing kept right on computing.

ZFS developers like to do this with hard drives :) But how did IBM do that with RAM ? Do mainframes have… redundant RAM? Like literally sticks mirroring others?

Yes.

Re: Hello World on z/OS

#78

Post by [deleted] » Tue, Jul 31, 2018, 5:53 PM UTC

[deleted]

Re: Hello World on z/OS

#79

Post by bri3d » Tue, Jul 31, 2018, 6:24 PM UTC

rbanffy wrote: post #75

walrus01 wrote: post #73

Earlier quoted context omitted.

The hard part for mainframes is that unlike Linux and the BSDs, you can't acquire a bunch of 4 year old Core i5 systems for $80 each (or sometimes free) and install a bunch of different OS varieties on them to test stuff in your home office or the bedroom of a bored teenager (example: centos hosting KVM VMs, debian + xen, freebsd on bare metal, etc).

With zSeries it's a bit harder, but for the iSeries (I still count AS/400 as alien enough to be "mainframes"), you can get machines for reasonable prices. The prices drop precipitously when that hardware is dropped from the last OS release. For Z machines, you can use Hercules as an acceptable approximation. A couple questions I posted as example are about Hercules.

There's no legal way for a hobbyist to run anything better than MVS 3.8j on Hercules and even if you're not morally opposed to piracy, z/OS is virtually impossible to find and configure.

Re: Hello World on z/OS

#80

Post by TheOtherHobbes » Tue, Jul 31, 2018, 6:45 PM UTC

mschaef wrote: post #29

wolfgke wrote: post #11

Earlier quoted context omitted.

> Linux and DOS/Windows have far more in common with each other than mainframe OSes, despite their huge differences, because they evolved from mini/microcomputers and UNIX. Surely Linux and the Windows NT line (don't confuse the Windows 9x line, which evolved indirectly from DOS with the Windows NT line) have much more in common with each other than mainframe OSes, but Windows did not evolve from UNIX: The Windows 9x…

> The Windows 9x line evolved indirectly from DOS Not sure what you believe to be 'indirect' about that relationship. That Windows codebase started out running on DOS and ultimately wound up so closely coupled that they shipped together in the same box as the same product. > Windows did not evolve from UNIX: Windows, through its DOS lineage, does indeed have some roots in the Unix tradition. (This should be unsurpris…

DOS commands and hierarchical file paths were based on DEC’s TOPS-10, via CP/M, both of which Cutler would have been familiar with.

DOS was at best a mongrel mash-up. It no more evolved from Unix than AmigaOS did.