man/man4/mem.4

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NAME            mem  --  core memory
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DESCRIPTION     mem\b\b\b___
is a special file that is an image of the core memory
of the computer.
It may be used, for example, to examine,
and even to patch the system using the debugger.

Mem\b\b\b___ is a byte-oriented file; its bytes are numbered
0 to 65,535.

If a non-existent memory location is
referenced, the user
suffers the resultant bus error.

Memory referenced through
the file is treated with movb\b\b\b\b____ instructions.
Certain device registers do not implement
DATOB cycles to odd addresses.
Other registers react strangely to this
addressing.
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FILES           /dev/mem
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SEE ALSO        --
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BUGS            --