3 ms·

Exactly! You will never learn anything about JCL from a COBOL textbook. Heck, I'm not sure a JCL textbook (if they exist?) would be of much help either. When

by mikece 4y ago

Exactly! You will never learn anything about JCL from a COBOL textbook. Heck, I'm not sure a JCL textbook (if they exist?) would be of much help either. When I went to college I was in the last group of students whose client/server classes were all mainframe based. We had a class where JCL was taught and a valid answer for "Why is JCL syntax so irregular?" on the exams was: "Because it was invented in Berkeley in the 1960s and everyone was on drugs."

schlauerfox 4y ago
I took an IBM mainframe intro course on Coursera and it was pretty good. I learned how to use the editor and menu thing. It was very out of my windows/linux/PC experience.
- ElectricalUnion 4y ago
  > the editor ed /s Well, you can invoke AIX and run ed, it works, but yes, ISPF, running in a 3270 terminal, is pretty weird. That being said, it's pretty much very interactive even under horrible latency because it sends the entire screen every repaint. 3270 is, in a retro way, what the web 1.0 would look like if we were limited to monospaced characters.
ElectricalUnion 4y ago
There was a ancient saying that new JCL is never written, just copied and modified until it works, because no one understands the entirely of it.
p_l 4y ago
The truth about JCL is actually worse than "they were on drugs". In fact, they gave themselves a goal of avoiding making it into a programming language, except unfortunately real life requirements meant it had to gather such features quickly. Other infamous components came because of need to specify in line all sorts of metadata for I/O, because the OS might not have a place to store it - this caused the infamous DD statement that /bin/dd is a joking refence to. In retrospective, one of the leads on JCL mentioned that they should have instead gone straight for a full programming language, that this way it would have better design.

by mikece 4y ago

schlauerfox 4y ago

I took an IBM mainframe intro course on Coursera and it was pretty good. I learned how to use the editor and menu thing. It was very out of my windows/linux/PC experience.

ElectricalUnion 4y ago
> the editor ed /s Well, you can invoke AIX and run ed, it works, but yes, ISPF, running in a 3270 terminal, is pretty weird. That being said, it's pretty much very interactive even under horrible latency because it sends the entire screen every repaint. 3270 is, in a retro way, what the web 1.0 would look like if we were limited to monospaced characters.

ElectricalUnion 4y ago

There was a ancient saying that new JCL is never written, just copied and modified until it works, because no one understands the entirely of it.

p_l 4y ago

The truth about JCL is actually worse than "they were on drugs". In fact, they gave themselves a goal of avoiding making it into a programming language, except unfortunately real life requirements meant it had to gather such features quickly. Other infamous components came because of need to specify in line all sorts of metadata for I/O, because the OS might not have a place to store it - this caused the infamous DD statement that /bin/dd is a joking refence to. In retrospective, one of the leads on JCL mentioned that they should have instead gone straight for a full programming language, that this way it would have better design.