Assembly / HLASM · Abend code
What does Abend S0C1 mean in Assembly / HLASM?
The CPU tried to execute an invalid operation code, most classically because execution fell through from the last real instruction straight into a data area (a DC or literal pool) and started trying to interpret raw data bytes as machine instructions.
The CPU tried to execute an invalid operation code, most classically because execution fell through from the last real instruction straight into a data area (a DC or literal pool) and started trying to interpret raw data bytes as machine instructions.
Check that every code path ends in an explicit branch back to the caller (typically BR 14) before any DC or literal declarations follow it. This is the single most common first-program mistake in assembler, catching even careful beginners who copy a working example and add code after it without an exit branch.