Hello World on z/OS • Hacker News Board

Re: Hello World on z/OS

#111

Post by southern_cross » Tue, Jul 31, 2018, 11:51 PM UTC

dragonwriter wrote: post #104

southern_cross wrote: post #102

Earlier quoted context omitted.

Don't forget that probably the only reason you can do a lot of that is because AT&T screwed up so badly legally back in the day, and lost many of their rights to Unix in the process. And if SCO had been successful in reasserting their rights to it not that long ago, you still might not be able to do it. IBM, on the other hand, has always competently (and sometimes quite viciously) protected their products legally. Th…

> IBM, on the other hand, has always competently (and sometimes quite viciously) protected their products legally. Viciously, perhaps. Competently...well, the Wintel PC market—long ago “The IBM-compatible PC market” might be an indicator that they can fall down hard on that.

IIRC, Compaq (remember them?) managed to come up with a clean-room PC BIOS clone, which started that whole ball rolling. Then, after IBM tried to re-establish control with the MCA (which folks pretty much immediately started trying to work around in various nefarious ways), Compaq also came up with EISA, which kind of blew that out of the water. In fact, IBM's original decision to work with mostly off-the-shelf parts in designing their PC (instead of home-grown stuff) pretty much came back to bite them here, but they were still in the PC/server business for quite a long time.

As for their other hardware, these days they're pretty much the only game in town for mainframe and midrange systems. And they jealously guard those markets, as lethargic as these may currently be.

Re: Hello World on z/OS

#112

Post by Koshkin » Tue, Jul 31, 2018, 11:51 PM UTC

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).

> Unix as the User Hostile Operating System

That would be UHOS, not UNIX.

Re: Hello World on z/OS

#113

Post by JdeBP » Wed, Aug 01, 2018, 12:08 AM UTC

Svip wrote: post #7

In the 'Allocate New Data Set' screenshot, it says - for the expiration date field - that the formats are 'YY/MM/DD, YYYY/MM/DD, YY.DDD, YYYY.DDD in Julian form, DDDD for retention periods in days or blank'. (I added some commas, which I assume are supposed to be there, but are just line breaks in the screenshot.) Does that mean z/OS supports the Julian calendar?

Three things are being erroneously conflated here.

* The Julian calendar, which actually has nothing to do with this field on the panel.

* The Julian day number, which is actually a day count since a point in the 48th century BCE, and again nothing actually to do with the panel.

* The day number of the year, which is sometimes colloquially, but erroneously, referred to as the "Julian day".

The panel is making that very error. It used to be a fairly common error, and you can see its echoes in the likes of "j" being a format specifier in various systems that expands to the day of the year. It is not so common, now. But it still happens occasionally.

* http://hannahlab.org/semantics-julian-day-vs-day-of-year/

* https://srfi.schemers.org/srfi-19/srfi-19.html

* https://www.science-emergence.com/Articles/How-to-convert-MO...

Re: Hello World on z/OS

#114

Post by chiph » Wed, Aug 01, 2018, 12:15 AM UTC

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.

When Java was first available on the AS/400 (ported by a man at IBM UK - I have forgotten his name), I tried to use SEU as my editor (me being a PC programmer). OMG worst experience ever.

Re: Hello World on z/OS

#115

Post by southern_cross » Wed, Aug 01, 2018, 12:40 AM UTC

forapurpose wrote: post #87

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?

Whenever I've laid hands on unfamiliar systems and their terminals, which has been a quite frequent occurrence over the years, one of the first things I've usually tried to do is get my hands on the terminal's handbook (or at least the condensed cheat-sheet version of it) to learn what all of its keys and key combinations did. (In this case the same would go for ISPF.) Assuming that the author is using some kind of 3270 emulation software, then she should have access to this stuff somewhere. In other words, she probably just needs to RTFM!

Re: Hello World on z/OS

#116

Post by southern_cross » Wed, Aug 01, 2018, 12:58 AM UTC

rbanffy wrote: post #71

voidmain0001 wrote: post #24

Earlier quoted context omitted.

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.

Unlike so many "modern" systems, these systems are designed to let you to put all of your eggs in one basket if you want to, and never even break a sweat! Their built-in level of reliability (they're almost bullet-proof) generally allows this, too. You may very well have legitimate reasons for not doing it, though, including regulatory requirements and such.

Re: Hello World on z/OS

#117

Post by rodgerd » Wed, Aug 01, 2018, 6:11 AM UTC

southern_cross wrote: post #110

rodgerd wrote: post #88

Earlier quoted context omitted.

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 r…

Given what is currently known today (there may be more bombshells yet to come) about x86 system- and chip-level vulnerabilities, both unintentional and intentional, I'm not sure that any sane CxO would allow their data to come anywhere near the platform if they were starting all over today again from scratch. Not that I would necessarily trust any other vendor either (especially not Microsoft), but still ... Always r…

s390x is subject to speculative execution attacks, just like x86_64. Your position appears to be rooted in superstition, rather than facts.

Re: Hello World on z/OS

#118

Post by trasz » Wed, Aug 01, 2018, 9:31 AM UTC

FWIW, this book ("Fake Your Way Through Minis and Mainframes" by Bob DuCharme) provides a good short user-level introduction to z/OS (and VM, and VMS, and...):

http://www.snee.com/bob/opsys/fullbook.pdf

Re: Hello World on z/OS

#119

Post by southern_cross » Wed, Aug 01, 2018, 1:41 PM UTC

rodgerd wrote: post #117

southern_cross wrote: post #110

Earlier quoted context omitted.

Given what is currently known today (there may be more bombshells yet to come) about x86 system- and chip-level vulnerabilities, both unintentional and intentional, I'm not sure that any sane CxO would allow their data to come anywhere near the platform if they were starting all over today again from scratch. Not that I would necessarily trust any other vendor either (especially not Microsoft), but still ... Always r…

s390x is subject to speculative execution attacks, just like x86_64. Your position appears to be rooted in superstition, rather than facts.

Indeed, but what is Intel up to these days - at least eight different variations of attack here? And let's not forget about the whole Intel ME thing, either.

BTW, just because a speculative execution attack or whatever is theoretically possible on an IBM system doesn't necessarily mean that it can be carried out in any practical sense, given the overall design of those systems and their general level of built-in security. But IBM can't just sit there and ignore the possibility, either.

Another problem they have these days relates to open source software and such, which they've been porting to their platforms much more lately. If a security patch for that software comes out then they still have to apply it, even if there may be no practical way to exploit it on their systems. And it can be quite unnerving to see long lists of such patches show up on a regular basis for systems which are otherwise generally considered to be rock solid.

Re: Hello World on z/OS

#120

Post by krylon » Wed, Aug 01, 2018, 4:20 PM UTC

southern_cross wrote: post #96

krylon wrote: post #52

Earlier quoted context omitted.

I wonder why they haven't developed a more human-friendly successor to JCL. I get that IBM's all about backward compatibility, but would it kill them to add a more accessible alternative? I once spent three days figuring out how to deal with an invocation that did not fit in an 80-character line. sigh

There was OCL on the IBM S/34 and S/36 back in the day, and there's CL on the IBM i today, which dates back to the earliest S/38 days (circa 1978). It's been some decades now since I've dealt with JCL, but as I recall both of those other languages make JCL look like child's play in comparison. Also, don't forget about Rexx!

Ugh, I tried to learn Rexx and I really did not like it. Maybe it is more "at home" on a mainframe, but playing with Regina Rexx on my desktop was no fun.

(Rexx has since developed an object oriented dialect, that might be more convenient to use.)