4 ms·

I would really enjoy getting the chance to hack on a mainframe. I have the idea that 40 (50?) years of continuously developed OS from OS/360->today must be some

by pnathan 16y ago

I would really enjoy getting the chance to hack on a mainframe. I have the idea that 40 (50?) years of continuously developed OS from OS/360->today must be something really amazing to use and to work with. But, last time I looked it was nearly impossible to get a login to one.

cosgroveb 16y ago
You're not missing much. I may be jaded however from my experiences "hacking" in school and at RandomBigCorp in COBOL and JCL (not to mention the joy of using the typical editors in those environments). You can use other languages like C but in a typical corporate environment you're not going to see a lot of code in anything other than COBOL. Writing code in assembly language on a mainframe my first year in college was actually a lot of fun. YMMV.
cosgroveb 16y ago
I forgot to mention that there are emulators out there. I have never used one but here's one from a quick google search: http://en.wikipedia.org/wiki/Hercules_(emulator) http://en.wikipedia.org/wiki/Hercules_(emulator) When I was in school, IBM occasionally had z/OS programming contests and would provide an environment for student competitors.
- bdb 16y ago
  Hercules is cool -- I last goofed around with it almost 10 years ago, but it was complete enough then to run VM/370 and MVS/370. If you're interested, start here: http://www.cbttape.org/vm6.htm http://www.cbttape.org/vm6.htm and http://www.bsp-gmbh.com/turnkey/ http://www.bsp-gmbh.com/turnkey/
jbarham 16y ago
"Continuous development" on the mainframe? Hah! My first job out of university in 1996 was doing COBOL programming on mainframes for the federal government of Canada, and my first project was to rewrite a program originally written in 1972 that had changed very little since then. I have little doubt that after almost 15 years my rewrite is still much the same. Anyway, I quickly realized that the mainframe environment doesn't exactly foster technical innovation so I moved on and am quite happy to have not sat in front a "green screen" in over a decade.
- mweatherill 16y ago
  Your experience is with an application running on a mainframe and is probably typical. The OP was referring to the OS itself which is continuously developed with fanatical dedication to backwards compatibility.
  - Someone 16y ago
    That "fanatical dedication to backwards compatibility" works even harder towards glacial development for the OS than for applications. Or do you think OS developers will ship a new, faster scheduler, tweak the memory allocator and the thread scheduler every month?
    - rbanffy 16y ago
      Plus, you won't get five nines reliability if you tweak the kernel every week. Mainframes are built to never stop, to never give you a headache and to never, ever surprise you.
whatusername 16y ago
I made an observation recently. I do a bunch of contracting for big companies: Working in a Windows environment -- you will be given Administrator access to anything you ask for. Working in a Linux environment -- you will be given a normal account and be able to SU to root Working in a UNIX (Solaris/AIX/HP-UX) environment -- you will be given a normal account and the option to SUDO certain commands Working in a zOS environment -- you wont be granted a login or allowed within 50 feet of the precious server.
jacques_chester 16y ago
Linux on zSeries doesn't run on z/OS at all. It runs on z/VM, a hypervisor that can either run purely as software, or hook into the PR/SM partitioning hardware built in the processors.

by pnathan 16y ago

cosgroveb 16y ago

You're not missing much. I may be jaded however from my experiences "hacking" in school and at RandomBigCorp in COBOL and JCL (not to mention the joy of using the typical editors in those environments). You can use other languages like C but in a typical corporate environment you're not going to see a lot of code in anything other than COBOL. Writing code in assembly language on a mainframe my first year in college was actually a lot of fun. YMMV.

cosgroveb 16y ago

I forgot to mention that there are emulators out there. I have never used one but here's one from a quick google search: http://en.wikipedia.org/wiki/Hercules_(emulator) http://en.wikipedia.org/wiki/Hercules_(emulator) When I was in school, IBM occasionally had z/OS programming contests and would provide an environment for student competitors.

bdb 16y ago
Hercules is cool -- I last goofed around with it almost 10 years ago, but it was complete enough then to run VM/370 and MVS/370. If you're interested, start here: http://www.cbttape.org/vm6.htm http://www.cbttape.org/vm6.htm and http://www.bsp-gmbh.com/turnkey/ http://www.bsp-gmbh.com/turnkey/

jbarham 16y ago

"Continuous development" on the mainframe? Hah! My first job out of university in 1996 was doing COBOL programming on mainframes for the federal government of Canada, and my first project was to rewrite a program originally written in 1972 that had changed very little since then. I have little doubt that after almost 15 years my rewrite is still much the same. Anyway, I quickly realized that the mainframe environment doesn't exactly foster technical innovation so I moved on and am quite happy to have not sat in front a "green screen" in over a decade.

mweatherill 16y ago
Your experience is with an application running on a mainframe and is probably typical. The OP was referring to the OS itself which is continuously developed with fanatical dedication to backwards compatibility.
- Someone 16y ago
  That "fanatical dedication to backwards compatibility" works even harder towards glacial development for the OS than for applications. Or do you think OS developers will ship a new, faster scheduler, tweak the memory allocator and the thread scheduler every month?
  - rbanffy 16y ago
    Plus, you won't get five nines reliability if you tweak the kernel every week. Mainframes are built to never stop, to never give you a headache and to never, ever surprise you.

whatusername 16y ago

I made an observation recently. I do a bunch of contracting for big companies: Working in a Windows environment -- you will be given Administrator access to anything you ask for. Working in a Linux environment -- you will be given a normal account and be able to SU to root Working in a UNIX (Solaris/AIX/HP-UX) environment -- you will be given a normal account and the option to SUDO certain commands Working in a zOS environment -- you wont be granted a login or allowed within 50 feet of the precious server.

jacques_chester 16y ago

Linux on zSeries doesn't run on z/OS at all. It runs on z/VM, a hypervisor that can either run purely as software, or hook into the PR/SM partitioning hardware built in the processors.