RAM and ROM Assignment PDF

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Difference between RAM and ROM and their types....

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Q1: Define and Differentiate between RAM and ROM. RAM The most common type of memory is called random access memory, otherwise known as RAM. Hence in terms of computers, the term memory is generally used to refer to RAM. The RAM holds data and program instructions whilst the CPU is using them. Hence RAM is temporary memory in that it temporarily holds onto data. RAM is volatile meaning it loses its contents when the computer is shut off or if there is a power surge/ failure. RAM has a huge impact on the speed and power of a computer, as the more RAM a computer has, the more it can do and the faster it can perform certain tasks. Memory is usually measured in bytes, of which 1 byte is composed of 8 bits. It can be measured in kilobyte, megabyte, gigabyte, and terabyte. ROM Unlike the RAM, read only memory (ROM) permanently stores data, even when the computer is off. The ROM is nonvolatile memory in that it never loses its contents. The ROM aids a computer in starting up in that it searches for specific directions in starting up (for example if you program your computer to boot from a flash drive), and for information about its hardware devices.

DIFFERENCES BETWEEN RAM AND ROM Temporary vs Permanent The RAM holds on to data temporarily whilst the ROM is considered permanent data. Storage Capabilities The ROM is non-volatile in that it doesn’t lose its data stored in the event of a power failure. Hence it doesn’t require a power source to store data. The RAM however is volatile as it loses the data stored in the event of a power surge or power issue and it requires power to store data. Uses The RAM is used in computers to temporarily store files on the computer, while the ROM is often used in the startup of the computer ie; it is used to store the BIOS (Basic Input Output System) program on the motherboard. Storage Capacity ROM chips tend to have a storage capacity of 4-8 MB while RAM chips tend to have a storage capacity of 1-256 GB. Hence the RAM can hold on to a massive amount of data, but only if there’s a power source. Physical Size The ROM can have a varying size as it can be less than an inch in length to multiple inches in length and width which depends on their use. The RAM however is more standardized, in that it is usually available in 2 primary sizes depending on if it is used in a desktop or a laptop. The desktop RAM is about 5 ½ inches in length and 1 inch in width. Laptop RAM is about half the length of the desktop RAM.

Q2: What are the different types of RAM and ROM. TYPES OF RAM AND ROM Types of RAM 

Static RAM, or (SRAM) It stores a bit of data using the state of a six transistor or memory cell. SRAM is generally used as a cache memory for processors. It is generally not replaceable by the end user. SRAM (static read only memory) does not have to be periodically refreshed. Static RAM provides faster access to data and is more expensive than DRAM. SRAM is used for a computer's cache memory and as part of the random-access memory digital-to-analog converter on a video card.

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Dynamic RAM, or (DRAM) It stores a bit data using a pair of transistor and capacitor which constitute a DRAM memory cell. Dynamic random-access memory (DRAM) is a type of RAM that stores data using a pair of transistors and capacitors. DRAM is comparatively cheaper than SRAM, but the operating speed is slow. Their replaceability makes them suitable for computer systems whose memory modules can be replaced/upgraded.

Types of ROM 

Programmable ROM PROM or programmable ROM (programmable read-only memory) is a computer memory chip that can be programmed once after it is created. Once the PROM is programmed, the information written is permanent and cannot be erased or deleted. If a PROM is programmed with an error or needs updated, the chip is discarded and a new PROM is created, replacing the old chip. PROM was first developed by Wen Tsing Chow in 1956. An example of a PROM is a computer BIOS in early computers. Today, PROM in computers has been replaced by EEPROM also known as electrically erasable programable read only rom.

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Erasable Programmable ROM EPROM is a non-volatile memory chip that can only be read. It was invented by Dov Frohman in 1971 while at Intel. If exposed to ultraviolet light, an EPROM can be reprogrammed if needed, but otherwise does not accept or save any new data. Hardware manufactures use EPROM when there may be a need for the data on the EPROM to be changed. An EPROM chip is distinguishable by a small quartz crystal in the form of a circle window that exposes the chip so that it be reprogrammed. Today, EPROM chips are not used in computers. They were replaced by EEPROM chips.

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Electrically Erasable Programmable ROM Short for electrically erasable programmable read-only memory, EEPROM is a PROM that can be erased and reprogrammed using an electrical charge. EEPROM was developed by George Perlegos while at Intel in 1978 and unlike most memory inside a computer, it remembers its data without power hence it is a non-volatile memory chip. Having a computer with an EEPROM allows the user to update the computer BIOS without having to open the computer or remove any chips.

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Mask ROM Unlike these other computer memory chips, Mask ROM (MROM) chips are produced by arranging transistors before the semiconductor manufacturing process begins. Often, Mask ROM (MROM) chips are used in computer systems that require long-term sustainability. Thus the data is written during the manufacturing of the memory chip and is manufactured with its contents....