supervisor call instruction การใช้

This was accomplished using an MVS emulator that intercepted system calls at the Supervisor Call instruction ( SVC ) level.
Most access to supervisor services is via system subroutines that issue the necessary Supervisor Call instructions ( SVCs ) rather than by direct use of SVCs.
In the IBM System / 360 mainframe family, a Supervisor Call instruction implements a system call for legacy facilities; the Program Call ( PC ) instruction is used for newer facilities.
The fact that and double-increment the program counter before pushing it to the stack facilitates the technique of treating them as supervisor call instructions, as found on some mainframe computers.
Indeed, the OS has a special facility for " fast fixing " these short-term fixed data buffers ( fixing which is performed without resorting to a time-consuming Supervisor Call instruction ).