Computer

Computer has become an essential tool in today’s life, it helps human to reduce work especially in work processing, mathematical solving and graphic processing. Today’s computer can even perform multi-tasking where several tasks can be done at the same time. All this performance requires memory. Computing memory had gone through a great advancement and development from olden days, even a memory device can be of the size of a thumb which allows us to carry it along. In this era of technology, computing memory are of different types and it designed for usage, thus it is crucial to know the development of computing memory and to understand the functionality of different type memory used in computers. The basic computer memory originated from an Analytical Engine which is capable of storing a program and performs mathematical calculation which was invented by Charles Babbage in 1834 after 10 years of research.[1] The idea of Babbage was controlled by a program of instructions on punched cards connected together with ribbons.[2] The development of computing memory had remained stagnant for 100 years until 1932, a man from Austria named Gustav Tauschek invented drum memory.[3] The drum memory is formed from a metal cylinder coated with recordable ferromagnetic materials which enable the reading of recorded data.[4] The drum memory is widely used throughout out 1950s and 1960s which had a memory capacity of 10kb.[5] In 1936, a German named Konrad Zuse had patent a mechanical memory based on sliding metal parts.[3] After three years, a 50-bit words digital memory was built by John Atanasoff and Clifford Berry in which the computer is named Atanasoff-Berry Computer. In 1941, an extraordinary breakthrough was made by Helmut Shcreyer where usage of neon lightning as a means of providing memory.[3] A German Engineer then invented a Z3 computer having 23-bit word length.[6] 1944, John von Neumann wrote the “First Draft of a Report on the Electronic Discrete Variable Automatic Computer(EDVAC)” which he outlined the architecture of a stored-program computer that has binary number system, internal memory and a program that can execute more tasks at the same time. [7][6]. Los Angeles, 1947, the memory module based on magnetism is perfected from magnetic drum memory. [3] Frederick Viehe, An Wang, Kenneth Oslen and Jay Forrester had contributed in the invention of magnetic core memory will pulse transfer control.[6] Jay Forrestor invented the magnetic random-access coincident-current drum.[6] Jay Forrester continued experimentation and in 1949, he came up with the idea of magnetic core memory with a grid of wires used to address the cores.[4] Within the same year, Maurice Wilkes assembled Electronic Delay Storage Automatic Calculator(EDSAC) using vacuum tubes and established a library of short programs called subroutines stored on punched paper tapes which had a memory of 1K words, 17 bits and mercury delay line.[7] Also in 1949, The Manchester Mark 1 computer with memory size of 128+1024 40 digit words became the pioneer of Ferranti Ltd. that completes the first commercial computer- Ferranti Mark 1 with 256 40-bit words of main memory and 16K words of drum memory that was built in 1951.[6][4] In 1950, ERA 1101 is built which is the first commercially produced computer that held 1 million bits on its magnetic drums. Drums registered information as magnetic pulses in tracks around a metal cylinder.[7] Drums stored as many as 4000 words.[7] Alan Turing built a digital calculator containing a delay line computer memory size of 352 32-digit words.[6] In 1951, Jay Forrester patents the matrix core memory and develops the MIT Lincoln Laboratory Whirlwind with a computer memory size of 2048 16-digit words and a magnetic drum, cathode ray tube and tape storage.[6] Within the same year, Remington Rand built the IBM UNIVAC with mercury delay lines memory and magnetic storage tape.[6] In 1952, the EDVAC computer is invented with 1024 44-bit words of ultrasonic memory, a core memory module is added to ENIAC computer. [3] 1953, IBM shipped its first electronic computer, the 701 which is the first store-program vacuum tube computer with a cathode

ray tube memory of 2K 36 bits words.[7][6] Kenneth Oslen built the Memory Test computer with ferrite-core memory in which a matrix of ferrite rings and cores wrapped with wires leading off to the sides.[8] UNIVA is the first commercial computer that incorporated technology of ferrite-core memory.[6] It was in 1961, the first transistorized 64-bit memory computer is invented. [6] In 1965, Maurice Wilkes introduced the idea of a cache computer memory. It is also the first integrated circuit random access memory based on Read Only Memory ROM. In 1968, Dynamic Random Access Memory DRAM was invented by Robert Dennard.[6] After a year, Intel begin to design chip and produced 1K RAM chip which is one of the largest chip producer up till now.[6] In 1971, Intel invented the 256-byte erasable read-only memory which is also now as EROM.[6] 1975, Lee Felsenstein designed the first memory-mapped alphanumeric Video Display Module(VDM).[6] The memory size of a memory module had continued its development until 1980, where Shugart and Associates produced the 5 1/2” Winchster disk drive floppy. Within the same year, Toshiba invented the first flash memory chip, using the technology of “flash” moniker where stored data could only be wiped with a bright UV light.[9] From that onwards, memory devices has deceases in its size with its memory size increases. 1981, Adam Osborne assembled the first portable computer consisting two 5 1/4inch floppy disk drives as memory module for the computer.[6] Then in 1984, Toshiba invented the NAND and NOR flash memories.[6] At the same time, the Apple Macintosh created a 3.5” 400-kilobyte floppy disk drive.[6] From the year 1986-1999, the SDRAM has undergone rapid development where higher frequency RAMs are created for faster data transfer. The RAM introduced at that time are extended Data Out EDO DRAM, the Synchronous Dynamic RAM, Direct Rambus RAM and Pseudostatic RAM. [6] In year 2000, a Double Data rate DDR SDRAM is introduced and used by IBM and Linux in operating computer memory device.[6] This DDR RAM has continued to develop until now to give higher frequency enabling faster data transfer.[6] In 2005, the new DDR2 RAM is introduced where it reaches 800MHz.[6] At the same time, Toshiba and SanDisk created the NAND 1 GB Multi-Level Cell MLC flash storage chip whereas Samsung developed the world’s first 2 GB memory chip.[6] In 2006, Samsung announces flash memory hard drives with capacity of 4 GB up to 8GB. [6] in 2007, DDR3 SDRAM replaces DDR2 SDRAM with a speed of 1066 up to 1333Mhz.[6] In short, memory refers to the physical devices used to store programs or data on a temporary or permanent basis for use in a computer or other digital electronic device [10] From the history of computing memory mentioned above, it is noticed that there types of memory used in computer- Random-Access Memory (RAM), Read Only Memory (ROM), Cache, Computer Hard Drive and Flash Memory. [11] Random Access Memory (RAM) is memory device that stores temporary data. The data is normally read from the hard disk and temporary stored in RAM and access by processor.[11] It is a volatile memory, as when the power is switched off, RAM losses all the data and it can only be retained or retrieve when the system is running. The data retrieved are in random order. [11] There are two types of RAM-Static RAM (SRAM) and Dynamic RAM (DRAM). SRAMs stored its data using latches and thus the stored data can be indefinitely long as long as dc power is applied.[12]On the other hand, DRAMs uses capacitors to store data which cannot retain data very long without the capacitors being recharged by a process called refreshing.[13] In today’s operating system, it is possible of extending the RAM by means of virtual memory. [13] For instance, the RAM has 1GB free spaces and the computer has 1 GB of page file, the operating system can swap memory making operating system with

2GB memory. This is the virtual memory that would help to speed of the processing of the computer.[13] Read Only Memory(ROM) semi permanently or permanently store data.[12] The data can be read from the memory device but cannot be changed at all or cannot be changed without proper equipment.[12] It stores memories that are repeatedly used in system applications for system initialization and operation.[12] ROM retains stored data even when the power is turned off thus making it a non-volatile memory.[12] There are 5 types of ROM namely Mask ROM, Programmable ROM(PROM), Erasable PROM (EPROM), Ultraviolet PROM(UV EPROM), Electrically Erasable PROM(EEPROM).[12] The mask ROM stores data permanently upon manufacturing procedure. The programmable ROM enables storage of data to be perform with the aid of specialize equipment.[12] The Erasable PROM (EPROM) is electrically programmable by the user. Another type of memory is known as the Flash Memory. Flash Memory is a nonvolatile device. It enables portable and convenient transfer of data between computers. The data in flash memory can be read or write by user.[11] Only a specific number of erase and write cycles it can be performed, after which it creates a tendency to lose out on the stored information. [11] There are two types of flash memory namely NAND and NOR. [14] The NAND type is primarily used in memory cards, USB flash drives, solid-state drives, and similar products, for general storage and transfer of data. [14] The NOR type, which allows true random access and therefore direct code execution.[14] Cache is type of memory where the computer can access more responsively than in the regular RAM. The CPU looks up at the cache memory before searching the required information from the central memory storage. [11]. This help to reduce the need of system to look for information in an larger and larger area, resulting in faster extraction of data.[11] A hard disk drive (HDD) is used for storing and retrieving digital information using rapidly rotating discs coated with magnetic material.[16] Data is written or read from the coating of the magnetic head which are highly sensitive and high-precision electromagnet.[17] A hard disk/drive unit comes with a set rotation speed varying from 4500 to 7200 rpm.[18] In conclusion, the memory technology is developing rapidly to meet the needs of our daily, from a small tiny memory strip and vacuum tube, it has become a very small chip memory device. There are actually three importance of the memories in computing which are help boosting the speed, performance and stability of computer systems.