Untitled Quiz

BCC Revision

• This is a revision document for a course of study.

Topic 1 Part 2

• No further details provided.

Third Generation (1960's – 1970's)

• Integrated circuits (ICs) were used.
• A single IC contained multiple transistors, resistors, and capacitors.
• Examples included IBM-360 series, Honeywell-60000 series, PDP (Personal Data Processor), IBM-370/168, and TDC 316.

Characteristics of Third Generation Computer

• Operating systems included remote, time-sharing, and multiprogramming.
• Programming languages included FORTRAN II to IV, COBOL, PASCAL, and BASIC.
• Compared to second generation, third-generation computers were smaller in size.
• Third-generation computers were still costly.
• They were more reliable.
• They were faster.
• They consumed less electricity and generated less heat.

Fourth Generation (1960's – 1970's)

• Very Large Scale Integrated (VLSI) circuits were used.
• VLSI integrated about 5000 transistors on a single chip.
• Examples include DEC 10, STAR 10000, PDP 11, CRAY-1 (Super Computer), and CRAY-X-MP (Super Computer).

Characteristics of Fourth Generation Computer

• Operating systems included time-sharing, real-time, networks, and distributed processing.
• Programming languages include C, C++, and DBASE.
• Compared to third generation, fourth generation computers were smaller in size.
• They were cheaper.
• They were portable and reliable.
• Computers became accessible more easily.
• The concept of the internet was introduced.

Topic 2 Part 1

• No further details provided.

PROCESSORS - CU & ALU

• Processors contain a Control Unit (CU) and an Arithmetic Logic Unit (ALU).
• The CU and ALU work together to process operations.
• Instructions transfer from storage to memory when a user runs an application.
• Data is transferred from input devices and storage devices to memory.
• The CU interprets and executes instructions in memory.
• The ALU performs calculations on data in memory.
• Results are stored in memory.

Control Unit

• The Control Unit (CU) directs and coordinates most computer operations.
• It interprets instructions from programs or applications and initiates actions to execute them.
• The CU directs internal components like the ALU, registers, and buses.

Arithmetic Logic Unit (ALU)

• The ALU performs arithmetic and comparison operations.
• It compares data items to decide if one is greater than, equal to, or less than the other.
• The comparison's results determine actions in the computer system.

SYSTEM CLOCK

• The system clock is a quartz crystal circuit.
• The clock controls the timing of all computer operations.
• It generates regular electronic pulses (ticks) to set the computer operating pace.
• A tick is equivalent to a clock cycle.
• Modern processors are superscalar, executing multiple instructions per clock cycle.
• Processor speed is measured in gigahertz (GHz).

MEMORY

• The system unit has two types of memory: Volatile and Non-Volatile.
• Volatile memory loses contents when power is off (e.g., RAM).
• Non-volatile memory retains content when power is off (e.g., ROM, flash memory, CMOS).

MEMORY - RAM

• RAM (random access memory) is main memory; chips can be read from and written to by the processor and devices.
• RAM loads operating system files during boot-up from storage.
• Applications and data load into RAM as needed.
• The processor interprets and executes instructions in RAM.
• RAM supports multiple simultaneous applications and programs.

MEMORY - RAM (Dynamic RAM)

• Dynamic RAM (DRAM) requires constant reenergizing to retain content.
• Different DRAM variations include SDRAM, DDR SDRAM, DDR2, DDR3, DDR4, and RDRAM.

MEMORY - RAM (Static RAM)

• Static RAM (SRAM) does not require frequent reenergizing to retain content.
• SRAM is faster than DRAM but more expensive.
• Special applications, like cache, use SRAM.

MEMORY CACHE

• Memory cache speeds up processes by storing frequently used instructions and data.
• Most PCs have level 1 (L1) and level 2 (L2) caches, and some have level 3 (L3) caches.
• L1 cache is built directly onto the processor.
• L2 cache is slightly slower than L1 but larger.
• L3 cache is on the motherboard and separate from the processor.
• The processor searches the cache for instructions and data when needed.

FLASH MEMORY

• Flash memory is non-volatile; data is retained when power is off.
• Flash memory allows for easy content updates and is used for start-up instructions.
• Devices that use flash memory include smartphones, media players, printers, digital cameras, and automotive devices.
• Flash memory stores data entered into devices.
• Removable devices such as memory cards use flash memory.

BUSES

• Buses are electrical channels that internally transmit bits in the computer's circuitry.
• They connect various devices within and attached to the computer's system unit.
• Data transfers between input devices and memory, from memory to the processor, from the processor to memory, and from memory to output devices.

MICR READER

• Magnetic Ink Character Recognition (MICR) devices read magnetized text.
• An MICR reader converts MICR characters into a form the computer can use.
• Bank checks use MICR.

Topic 2 Part 3

• No further details provided.

PRINTERS - Thermal Printer

• Thermal printers use heat to produce images on thermal paper.
• They do not require toner or ink.
• The types of paper used are thermal paper.

PRINTERS - Dot-Matrix Printer

• Dot-matrix printers use pins to strike an inked ribbon against paper.
• Print quality is moderate (not high resolution) as the technology is older.

Topic 2 Part 4

• No further details provided.

SEQUENTIAL & DIRECT ACCESS

• Sequential access requires reading or moving through all information up to the point needing to be read or written.
• Tape drives are an example of sequential access.
• Direct access finds data by deriving its storage address.

HARD DISK

• A hard disk is a storage device with platters and magnetic particles to store data, instructions, and information.
• Capacity depends on the number of platters and the magnetic coating composition.
• Storage capacity is determined by the number of platters and density (amount of data in an area of the storage).

How a Hard Disk Works

• The head actuator moves the read/write heads to the correct data location on the platters.
• The platters spin while reading/writing data.
• The circuit board controls head actuator movement.
• Software determines the data location.

TAPE

• A tape is a magnetically coated plastic ribbon.
• Tapes are capable of storing large amounts of data.
• Tape drives read and write data to tapes.

Topic 4

• No further details provided.

NIELSEN'S TEN USABILITY HEURISTICS

• #3 User control and freedom: Users need clear ways to undo mistakes.
• #4 Consistency and standards: Actions should mean the same thing.

Topic 6

• No further details provided.

Image File Type – PNG

• Portable Network Graphics (.png)
• Lossless compression
• Best for web images; supports 16 million colors.

Image File Type – JPEG

• Joint Photographic Experts Group (.jpg or .jpeg)
• Lossy compression
• Smaller file sizes; good for web images and non-professional printing.