MEM(4) MachTen Programmer’s Manual MEM(4)

NAME
mem, kmem - main memory

DESCRIPTION
The file /dev/mem is an interface to the physical memory of the computer.
Byte offsets in this file are interpreted as physical memory addresses.
Reading and writing this file is equivalent to reading and writing memory
itself. An error will be returned if an attempt is made to reference an
offset outside of /dev/mem.

Kernel virtual memory is accessed via the file /dev/kmem in the same man-
ner as /dev/mem. Only kernel virtual addresses that are currently mapped
to memory are allowed.

MachTen
On the Macintosh, physical memory starts at 0x00000000, and is contigu-
ously mapped after that.

FILES
/dev/mem
/dev/kmem

HISTORY
The files mem and kmem appeared in Version 6 AT&T UNIX.

4.4BSD June 5, 1993 1