1.  INDEX
 Introduction
 History
 Types of ram
 Technology in ram
 New in ram

2.  INRODUCTION
 RAM is basically a computer's short-term memory, it
temporarily stores the information a program requires
to run while it is running. RAM runs at a very high
speed when compared to hard-drive speed because it is
used and needed more. In fact RAM is so important
that RAM size and speed can play an equal or greater

3. part in the computer's speed than the CPU. However
the data stored in RAM is lost when the computer is
switched off, so it can’t be used for long term storage.
Modern computers can get up to 4GB of ram, and
512MB is required to install the latest version of
Windows, "Vista." In a modern operating system,
when a program starts, it allocates a small portion of
RAM to itself. Upon loading files or data, the size of
RAM it takes up will increase. Upon closing the
program, the memory is freed up for other programs to
use.
RAM also known as Random Access Memory
can be explained as follows. Think of RAM as your
desk where you do homework or pay bills, you have
your bills or homework on top of the desk working on
it, so memory is where the open programs,
spreadsheets, iTunes and/or web browsers reside, once
you close out a program the information is then stored
on the hard drive. Since a portion of the operating
system is loaded into memory when the system boots
up, the more memory you have the larger the portion
of the OS can be loaded which allows the system to
perform faster. With the introduction of 64bit
operating systems the amount of memory has greatly
increased to 16GB - 48GBs of memory can now be
loaded into a personal computer allowing for a lot
faster load times and more information to be accessed
very quickly. With the introduction of DDR2 and
DDR3 memory the speed and the threads the computer

4. can use has increased and so systems have become
more efficient..
 HISTROY
Early computers used relays, mechanical counters or delay lines for main
memory functions. Ultrasonic delay lines could only reproduce data in
the order it was written. Drum memory could be expanded at relatively
low cost but efficient retrieval of memory items required knowledge of
the physical layout of the drum to optimize speed. Latches built out
of vacuum tube triodes, and later, out of discrete transistors, were used
for smaller and faster memories such as registers. Such registers were
relatively large and too costly to use for large amounts of data; generally
only a few dozen or few hundred bits of such memory could be provided.
The first practical form of random-access memory was the Williams
tube starting in 1947. It stored data as electrically charged spots on the
face of a cathode ray tube. Since the electron beam of the CRT could read
and write the spots on the tube in any order, memory was random access.
The capacity of the Williams tube was a few hundred to around a

5. thousand bits, but it was much smaller, faster, and more power-efficient
than using individual vacuum tube latches. Developed at the University
of Manchester in England, the Williams tube provided the medium on
which the first electronically stored-memory program was implemented
in the Manchester Small-Scale Experimental Machine (SSEM) computer,
which first successfully ran a program on 21 June 1948. In fact, rather
than the Williams tube memory being designed for the SSEM, the SSEM
was a testbed to demonstrate the reliability of the memory.
Magnetic-core memory was invented in 1947 and developed up until the
mid-1970s. It became a widespread form of random-access memory,
relying on an array of magnetized rings. By changing the sense of each
ring's magnetization, data could be stored with one bit stored per ring.
Since every ring had a combination of address wires to select and read or
write it, access to any memory location in any sequence was possible.
Magnetic core memory was the standard form of memory system until
displaced by solid-state memory in integrated circuits, starting in the
early 1970s. Robert H. Dennard invented dynamic random-access
memory (DRAM) in 1968; this allowed replacement of a 4 or 6-transistor
latch circuit by a single transistor for each memory bit, greatly increasing
memory density at the cost of volatility. Data was stored in the tiny
capacitance of each transistor, and had to be periodically refreshed every
few milliseconds before the charge could leak away.
Prior to the development of integrated read-only memory (ROM)
circuits, permanent (or read-only) random-access memory was often
constructed using diode matrices driven by address decoders, or specially
wound core rope memory planes.

6.  The Future Of Computer Memory
A thought about the future of computer memory -- the first era lasted
roughly 10 years, the second 20 years. We are now at 30 years of
semiconductor memory. Whats next? Will Terabytes of information be
stored in suger cube sized chrystals? Will neural networks contain
trillions of molecules of bits?
 Types of RAM
There are two different types of RAM:
 DRAM (Dynamic Random Access Memory)
 SRAM (Static Random Access Memory).
The two types of RAM differ in the technology they use to hold data, with DRAM
being the more common type. In terms of speed, SRAM is faster. DRAM needs to
be refreshed thousands of times per second while SRAM does not need to be
refreshed, which is what makes it faster than DRAM. DRAM supports access times of about 60
nanoseconds, SRAM can give access times as low as 10 nanoseconds. Despite
SRAM being faster, it's not as commonly used as DRAM because it's so much
more expensive. Both types of RAM are volatile, meaning that they lose their
contents when the power is turned off.

7.  TECHNOLOGY
ABOUT RAM
In order to enable computers to work faster, there are several types of memory
available today. Within a single computer there is no longer just one type of
memory. Because the types of memory relate to speed, it is important to
understand the differences when comparing the components of a computer.
SIMM (Single In-line Memory Modules)
SIMMs are used to store a single row of DRAM, EDO or BEDO chips where
the module is soldered onto a PCB. One SIMM can contain several chips.
When you add more memory to a computer, most likely you are adding a
SIMM.
The first SIMMs transferred 8 bits of data at a time and contained 30 pins.
When CPU's began to read 32-bit chunks, a wider SIMM was developed and
contained 72 pins.
72 pin SIMMS are 3/4" longer than 30 pin SIMMs and have a notch in the
lower middle of the PCB. 72 pin SIMMs install at a slight angle.

8. DIMM (Dual In-line Memory Modules)
DIMMs allow the ability to have two rows of DRAM, EDO or BEDO chips.
They are able to contain twice as much memory on the same size circuit board.
DIMMs contain 168 pins and transfer data in 64 bit chunks.
DIMMs install straight up and down and have two notches on the bottom of the
PCB.
SODIMM (Small Outline DIMM)
SO DIMMs are commonly used in notebooks and are smaller than normal
DIMMs. There are two types of SO DIMMs. Either 72 pins and a transfer rate
of 32 bits or 144 pins with a transfer rate of 64 bits.
 RDRAM - RIMM
Rambus, Inc, in conjunction with Intel has created new technology, Direct
RDRAM, to increase the access speed for memory. RIMMs appeared on
motherboards sometime during 1999. The in-line memory modules are
called RIMMs. They have 184 pins and provide 1.6 GB per second of peak
bandwidth in 16 bit chunks. As chip speed gets faster, so does the access to
memory and the amount of heat produced. An aluminum sheath, cal led a
heat spreader, covers the module to protect the chips from overheating.
 NEW IN RAM
New chips that blur the line between computer memory and storage
are starting to move beyond niche applications and could change how
we use PCs, an industry analyst said Sunday.
The chips would enable the same instant-on capability that’s common
on tablets, but at much higher performance, said Tom Coughlin,
founder of Coughlin Associates.

9. ”We’re seeing the development of new solid-state storage
technologies that are starting to play a role,” he said. “MRAM is one
that we’re seeing playing a role providing a non-volatile memory
technology, and there’s some talk about resistive RAM doing some
things.”
Conventional memory chips—called DRAM—store ones and
zeros using a electrical charge in each memory cell, but
Magnetoresistive RAM (MRAM) uses a magnetic charge. Resistive
RAM (RRAM) is based on a sandwich made from two materials, with
the center layer having a different resistance to the material that
makes up the outer layers.
”Some of these new technologies that have been in the lab and have
been finding niche applications have been getting a little bit more
widespread,” said Coughlin. He was speaking at the Storage Visions
conference happening on the sidelines of the International CES in Las
Vegas.
THE END