Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Hello World on z/OS

medium.com

Post reply on HN
Print view View original

81–90 of 123 posts

Re: Hello World on z/OS

#81

Post by 394549 »

AnIdiotOnTheNet wrote: post #14

> IBM uses special and completely unintuitive names for basic concepts…. because OF COURSE THEY DO. As I recall, it's called "Bluespeak", and that sort of thing is pretty common actually. I was educated in networking at a Cisco netacad, so I use Cisco terminology that is apparently not universal. Programming languages do this too for some reason: Sum type, tagged union, discriminated union, variant...

>> IBM uses special and completely unintuitive names for basic concepts…. because OF COURSE THEY DO.

> As I recall, it's called "Bluespeak", and that sort of thing is pretty common actually.

How much of that is because they invented terms for these concepts before our current terms were coined or became ubiquitous? It might be easy to forget, but IBM was once at the cutting edge of computing. They coined terms, others coined rival terms, and it wasn't at all clear whose terms would be ubiquitous in 2018. IBM changing to adopt another computing culture's terms would be akin to metrification: expensive, short term pain to abandon a good-enough system to achieve distant long-term benefits.

Re: Hello World on z/OS

#82

Post by mschaef »

TheOtherHobbes wrote: post #80
mschaef wrote: post #29

Earlier quoted context omitted.

> 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.

> 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.

I'm sure he was, but DOS got pathnames in March of 83 and Cutler didn't join until 6 years later.

Re: Hello World on z/OS

#83

Post by southern_cross »

As someone who has been in IT for decades now and who over the years has moved between IBM, Wang, Sperry, DEC, Unix, DOS, Windows, Teradata, etc. platforms with aplomb, this article just has "Noob!" written all over it. :)

Re: Hello World on z/OS

#84

Post by forapurpose »

krylon wrote: post #59
floatboth wrote: post #32

Earlier quoted context omitted.

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?

I have seen one PC-based server that had redundant RAM. I never tried pulling out RAM modules, but I guess there is not much point in having a RAID1-like arrangement for RAM if the machine cannot handle random RAM modules dying without crashing the OS. And it wasn't even a super high-end system.

> I have seen one PC-based server that had redundant RAM

Yes, I've seen this too, and on lowish-end servers.

Re: Hello World on z/OS

#85

Post by rodgerd »

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.

Doesn't help when your mainframe's infiniband controllers shit the bed and take the whole box down (a thing which has happened to me).

Re: Hello World on z/OS

#86

Post by southern_cross »

tolle wrote: post #76
bonzini wrote: post #55

Earlier quoted context omitted.

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.

I think SEU is far better than you seem to giving it credit for. In fact, I used it for decades and my only real complaints about it started when IBM stopped actively maintaining it. Over the years I also tried using various other "modern" editors, only to eventually cast them aside as being too unstable, buggy, or just slow and clunky (like Eclipse). In fact, I can only recall one particular instance where using such an editor (Eclipse in this case) actually proved unquestionably advantageous over using SEU, but even then I quickly got annoyed at some of the stupid (IMO) implementation details of it.

Re: Hello World on z/OS

#87

Post by forapurpose »

landbeyond wrote: post #36

Hilarious! (disclosure: I am a mainframe systems op/dev) The best part is where they didn't know about the INSERT key. I can understand z and ISPF being a hassle if you're used to modern computing but the mainframe logic is actually logical, and probably predates whatever modern stuff you're on to... like "files". :)

> Hilarious!

Give us the perspective from the other end of the learning curve: If you were the author, how would you start learning these things?

Re: Hello World on z/OS

#88

Post by rodgerd »

mattzito wrote: post #16

The mainframe infrastructure is both the core feature and showstopper bug of the platform. On the plus side, it has empowered countless core business applications to scale years, even decades, beyond their original development lifecycle. On the negative side, it has created a stagnant cult of mainframe “priests” who oversee a platform that most businesses would rather get rid of, if they could only figure out how. My…

The sales job Amazon et al did in convincing the world resilience was the job of app developers, not the system vendor, was quite impressive. And while it's true that commodity folks could stand to learn from mainframe folks - serverless looks quite a lot like a forty years on re-invention of CICS if you squint a bit - your story reminds me how profoundly true the opposite is, as well.

I've been part of a team that ran Linux on s390x, and it was a great exercise in demonstrating that however reliable your mainframe, it's still a SPOF. Even if you don't have my bad luck of four catastrophic hardware failures in as many years, your one reliable box still depends on the power, network fabric, storage fabric, etc at a single site. If you want to avoid losing your business when a sparky screws up, you need... several mainframes. At which point you're spending an absolutely astronomical amount to either sysplex, or you're building resilience into your applications, just like a bitty box.

And yes, so many mainframe folks are so very out of touch with the broader world. In around 2016 I had the supposed regional tech expert on z-Series system lecture me (rather snidely) on how:

1. s390 processors were 20 - 40 times more performant that Intel processors (demonstrably not true for any workload I cared about). 2. You could not do virtualisation on x86_64. It was impossible. With a straight face, in the year 2016, this guy told me, and clearly believed, that it was not possible to run heterogenous virtualised workloads on an Intel processor. Apparently tens of billions of Jeff Bezos' net worth literally did not exist for him.

There was more, but it was like talking to someone who had been frozen in a block of ice since 1996.

Re: Hello World on z/OS

#89

Post by rbanffy »

bri3d wrote: post #79
rbanffy wrote: post #75

Earlier quoted context omitted.

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.

There is a Hercules-like product made by IBM that can legally run z/OS, the Z Development and Test Environment. It's expensive, but legal.

Also, a surprising number of concepts of MVS 3.8j are present in z/OS, so what you learn there is not wasted. As the article points out, a lot still spins around 80-column punched cards. If you go for the less bare distributions of MVS, you'll see lots of software that tries to replicate the functionality of newer releases.

As an example, I pinged Cincom Systems to see if they had an old version of Mantis that could run on MVS 3.8 that I could obtain for free (Mantis was the language I used on mainframes). To my surprise, that version is still a commercial product and is fully supported. Things dom change very slowly in mainframe land.

Re: Hello World on z/OS

#90

Post by rbanffy »

rbanffy wrote: post #66
nine_k wrote: post #33

This is a nice reminder about how one feels when one meets a piece of technology for which one's intuition can't offer anything useful, many "common sense" assumptions end up incorrect, and you don't even know the right words to feed to a web search engine. I'll try to memorize this feeling, and remember it every time I try to explain something technical to people outside that field. Maybe it will help me explain bet…

I remember when someone referred to Unix as the User Hostile Operating System. They obviously never used MVS (z/OS's ancestor), OS/400 (now I/OS or something like that) or Burroughs' MCP (when an OS lends its name to a movie super villain, you have to respect it).

BTW, there's an interesting backstory on how MCP ended up being Tron's villain: Bonnie MacBird, who co-authored the story with Steven Lisberger, is Alan Kay's wife and Alan Kay was working at Unisys (or Burroughs) at the time she wrote it, as well as being an advisor to Lisberger and his partner and producer Donald Kushner.
Post reply on HN