Page 206 - Concise Encyclopedia of Robotics

Memory Organization Packet
Read-only memory (ROM and PROM)
By contrast to RAM, read-only memory (ROM) can be accessed, in whole
or in part, but not written over. A standard ROM is programmed at the
factory. This permanent programming is known as firmware. There are
also ROM chips that a user can program and reprogram. This type of
memory is known as programmable read-only memory (PROM).
Erasable PROM
An erasable programmable read-only memory (EPROM) chip is an IC
whose memory is of the read-only type, but that can be reprogrammed
by a certain procedure. It is more difficult to rewrite data in an EPROM
than in a RAM; the usual process for erasure involves exposure to ultra-
violet (UV) radiation.An EPROM chip can be recognized by the presence
of a transparent window with a removable cover, through which the UV
is focused to erase the data. The chip must be taken from the circuit in
which it is used, exposed to the UV for several minutes, and then repro-
grammed via a special process.
There are EPROMs that can be erased by electrical means. Such an IC is
called an electrically erasable programmable read-only memory (EEPROM).
These chips do not have to be removed from the circuit for reprogramming.
See also INTEGRATED CIRCUIT.
MEMORY ORGANIZATION PACKET
One of the most promising aspects of artificial intelligence (AI) is its use
as a tool for predicting future events, based on what has happened in the
past. This process is helped by arranging the computer memory into
generalizations called memory organization packets (MOPs). Some crude
examples of MOPs are the following statements:
• If the wind shifts to the east and the barometer falls, it will usually
rain (or snow in the winter) within 24 hours.
• If the wind shifts to the west and the barometer rises, clearing will
usually occur within a few hours.
• Light winds and a steady, high barometric pressure usually mean
little weather change for at least 24 hours.
• Foul weather with a steady, low barometric pressure usually means
bad weather for at least the next 24 hours.
These are broad generalizations, and they apply only in certain parts of
the world (the temperate latitudes over land), but they are MOPs based
on the experience of meteorologists over the past several centuries.
In AI, the system can be programmed to find the most valid MOPs

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