Experiment
What is HLASM?
High Level Assembler (HLASM) is the assembly language for IBM Z mainframes. It powers critical global infrastructure like airline reservations and banking. It's incredibly low-level, powerful, and very nerdy.
I work on this daily at Air New Zealand. While we can't spin up an actual z/OS environment in your browser, I built this tiny interactive mock terminal to give you a taste of what coding a loop in HLASM looks like.
Try running the predefined "Hello World" loop job, or break it by removing the #EDO tag and see what happens!
IBM 3270 TERMINAL EMULATORA.B. SYS
// ISPF EDITOR - HLASM.SRC
// SDSF OUTPUT
READY.