INTRODUCTION:
A computer system consists of several units, each unit was assigned to the carry-out specific function. This will combine together to give output to the user. In this post, you will be thought several computer units. Each unit has its own task to performed, combining their task is will make complete computer system
Arithmetic/ Logical Unit (ALU):
It was responsible for conducting arithmetic and logic operation on data, it depends on which data you are working on and determine by CU. It is cleared that, computer understand binary numbers which used by the logical operation.
Control Unit:
It provides the timing queue for all other units operation and its control signal. It consists of the logical and timing circuit that produce the proper signal enough to execute each instruction in a program. It controls the instruction word to the logic unit in binary form and then decoded to control unit. Combination of ALU and CU will give the CPU of the computer.
Memory Unit:
Any electronics a circuit that has the ability to retain its response to a momentary input is referred to as memory. It provides a way of storing binary numbers that are 0 and 1 either temporary or permanently, such as RAM or ROM.
Differences between RAM and ROM
RAM
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ROM
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It has a read-write attribute, which makes it suitable for storing data.
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It is a read-only memory, it taking care code
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It is volatile.
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The user loses all data in RAM if the computer turns off.
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Turn off the computer did not erase its data.
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It accesses data randomly.
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It cannot be written over.
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It took care of all the currently open applications at a time.
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It took care of BIOS.
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It cannot hold data without power ON.
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It can hold data in absent of power supply.
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It has transient behaviour.
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It is not transient.
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It can be removed for repair or upgrading.
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It is soldered on the motherboard.
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It has the colour code.
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It has no colour code.
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Writing data is fast in RAM
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It is a slower process for writing data.
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It can store multiple Gigabytes of data from 1GB – 256GB/chip.
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It stored several MB of data, such as 4mb or 8MB/chip.
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It has fasted type of memory in the computer; it can quickly switch between tasks very fast.
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It is used in gaming system cartridges like a Game Boy.
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Computer Memory Calculations:
It is necessary for the computer user to know how to calculate memory space and also the number of words in a document.
Example 1. Calculate memory space, words in a document with 2MB X 8?
Solution: 2MB = 2 X 1048576=2097152X 8= 16.777216 words.
Example 2. A semiconductor memory chip is rated 3K X 8. Find the following:
1. Amount of words that can be stored on it?
2.Word size?
3Total number of bits the clip store?
Solution:
1. 3K = 3 X 1024 = 3072.
2. Each word is 8bits (one byte).
3. Total number of bits 24576 bits. Example 3. Compare the bellow memories, which one has bigger size?
5MB X 8 Memory and 1M words at word size of 16bits. Solution:
6MB = 6 X 1048576 X 8 = 6291456bits.
1MB X 16 = 1048576 X 16 = 16777216bits. Hence, 6MB X 8 Memory stored more bits.
Computer memory can be internal such as hard disk, RAM, ROM. Also, there is an external memory such as an external hard disk, Flash driver, scan disk and CD/DVD disc.
Memory must be given attention in handling it because the virus can attack it at any given time without notice. Therefore Antivirus is the way out for securing your memories. Also, cleaning the external memory from dust or humidity is a good activity to have a secure memory.
External Cache Memory:
This is a memory build in computer processor to improve the performance of the system. It is also called level 1 cache or internal cache. It runs at the speed of the CPU, such as 3.0GHz. This has a lot of function more especially during browsing through the internet.
BIOS/Firmware:
The firmware- is a low-level software stored on a semiconductor chip that controlled:
- How the processor and chipsets interact with the installed operating system.
- It helps to detect hardware.
- It allocates system resources to it.
- The BIOS is a dual-line chip with 28 or 32 pins. It is activated immediately computer system turn ON.
CMOS Battery (Complimentary Metallic-oxide Semiconductor):
Is a memory used to stores certain computer setting such as Date and Time settings, It has round socket to be plug in. It is usual battery can become weak as a result of long-term working, CMOS battery also can be weak, the symptom is when your computer cannot update its date and time.
References:
Sharhamak Computer Institute (SCI).
Sahihiyar Rayuwa Association.
