The command in most
microcomputer BASICs for reading
memory contents (a byte) at an absolute address. POKE is the
corresponding command to write a value to an absolute address.
This is often extended to mean the corresponding constructs in
any
High Level Language.
Much hacking on small
microcomputers without
MMUs consists
of "
peek"ing around memory, more or less at random, to find
the location where the system keeps interesting stuff. Long
(and variably accurate) lists of such addresses for various
computers circulate (see
interrupt list). The results of
"poke"s at these addresses may be highly useful, mildly
amusing, useless but neat, or total
lossage (see {killer
poke}).
Since a
real operating system provides useful, higher-level
services for the tasks commonly performed with peeks and pokes
on micros, and real languages tend not to encourage low-level
memory groveling, a question like "How do I do a
peek in C?"
is diagnostic of the
newbie. Of course,
operating system
kernels often have to do exactly this; a real
C hacker
would unhesitatingly, if unportably, assign an absolute
address to a pointer variable and indirect through it.
[
Jargon File]
(1995-01-31)