Before revision: The S/360 has four I/O instructions: Start I/O (SIO), Test I/O (TIO), Halt I/O (HIO) and TestChannel (TCH).
After revision: I/O instructionsThe S/360 has four I/O instructions: Start I/O (SIO), Test I/O (TIO), Halt I/O (HIO) and TestChannel (TCH).