mem - main memory
mem is a special file that is an image of the main memory of the
computer. It may be used, for example, to examine and patch the
Byte addresses in mem are interpreted as physical memory addresses.
References to non-existent locations cause errors to be returned.
File kmem is the same as mem except that kernel virtual memory rather
than physical memory is accessed. Please refer to kmem(7) for
information about ioctl operations that are supported on /dev/kmem.
Examining and patching device registers is likely to lead to
unexpected results when read-only or write-only bits are present.
Hewlett-Packard Company - 1 - HP-UX Release 11i: November 2000