Execute Channel Program

<p>In <a href="/facts/IBM_mainframe/0kPkgADx">IBM mainframe</a> <a href="/facts/Operating_system/8XTuvMh2">operating systems</a>, Execute Channel Program (EXCP) is a <a href="/facts/Macro_(computer_science)/7abAsm1o">macro</a> generating a <a href="/facts/System_call/NW44AFJr">system call</a>, implemented as a <a href="/facts/Supervisor_Call_instruction/cspplehM">Supervisor Call instruction</a>, for low-level device access, where the programmer is responsible for providing a <i><a href="/facts/Channel_program/vDBtN2wQ">channel program</a></i>—a list of device-specific commands (CCWs)—to be executed by I/O channels, control units and devices. EXCP for <a href="/facts/OS%2f360_and_successors/nQbdNbx6">OS/360 and successors</a> is more specifically described in the OS System Programmer's Guide.; EXCP for <a href="/facts/DOS%2f360_and_successors/bT9PzVHd">DOS/360 and successors</a> is more specifically described in DOS Supervisor and I/O Macros.
This article mostly reflects OS/360 through <a href="/facts/Z%2fOS/amLCAlgV">z/OS</a>; some details are different for TOS/360 and DOS/360 through <a href="/facts/Z%2fVSE/b6Hnxc2p">z/VSE</a>.
</p>

Execute Channel Program open-in-new

Execute Channel Program