mem, kmem, null \*- core memory
is a special file that is an image of the core memory
It may be used, for example, to examine,
and even to patch the system using the debugger.
is used directly as a UNIBUS address.
References to non-existent locations cause errors to be returned.
Examining and patching device registers is likely
to lead to unexpected results when read-only or write-only
except that kernel virtual memory
rather than physical memory is accessed.
In particular, the I/O area
is located beginning at 160000 (octal)
The 1K region beginning at 140000 (octal)
is the system's data for the current process.