I compile/assemble COBOL and IBM's assembly language on a z13 daily and it's pretty much instantaneous.
Oh, I was talking more about older ways to organize the data centre: batch vs timeshare processing.
https://en.wikipedia.org/wiki/Time-sharing
I develop mainframe software.
I think the Redbook titled z/OS Basics has some JCL examples and exercises in it.
I also found this through a quick search: http://www.ibm.com/support/knowledgecenter/zosbasics/com.ibm...
I compile/assemble COBOL and IBM's assembly language on a z13 daily and it's pretty much instantaneous.