sys-break(2) - Unix First Edition Manual Page
11/3/71SYS_BREAK (II)

NAME break -- set program break
SYNOPSIS sys break; addr / break = 17.
DESCRIPTION break sets the system's idea of the highest location usedby the program to addr. Locations greater than addr and

below the stack pointer are not swapped and are thusliable to unexpected modification.

If the argument is 0 or higher than the stack pointer theentire 4K word user core area is swapped. When a program begins execution via exec the break is set,at the highest location defined by the program and data storage areas. Ordinarily, therefore, only programs withgrowing data areas need to use break.

DIAGNOSTICS none; strange addresses cause the break to be set toinclude all of core.

OWNER ken, dmr