IMPORTANT TERMS AND SUMMARY OUTLINE
accumulator |
CISC |
kilobyte (KB) |
Operand |
address |
control unit |
machine cycle |
Operation code |
alpha |
data mining |
machine language |
(op-code) |
alphanumeric |
decimal |
massively parallel |
parallel processing |
arithmetic and logic unit |
decoder |
processing (MPP) |
primary storage |
ASCII |
encoding system |
megabit (Mb) |
Program register |
ASCII-8 |
execution time (E-time) |
megabyte (MB) |
programmable read |
binary |
flash memory |
megahertz (MHz) |
only memory (PROM) |
bit |
FLOPS |
memory dump |
Register |
bubble memory |
GFLOPS |
MIPS |
RISC |
byte |
gigabyte (GB) |
neural network |
secondary storage |
cache memory |
hexadecimal |
nondestructive read |
terabyte (TB) |
central processing unit |
instruction register |
nonvolatile memory |
volatile memory |
(CPU) |
instruction time (I-time) |
numeric |
word |
channel |
kilobit (Kb) |
octal |
1- Data Storage: Data ill the Computer
Data, not information, are stored in a computer system. Data are stored temporarily during processing in primary storage (RAM) and permanently on secondary storage devices, such as magnetic tape and disk drives.
2- A Bit about the Bit The two electronic
states of the computer–on and off-are represented by a bit, short for binary digit.
These electronic states are compatible with the binary numbering system. Letters and decimal numbers are translated into bits for storage and processing on computer systems
3- Encoding Systems: Combining Bits to Form Bytes
Alphanumeric (alpha and numeric) characters are represented in computer storage by (combining strings of bits to form unique bit configurations for each character. Character-, are translated into these bit configurations, also called bytes, according to a particular coding scheme, called an encoding system. Popular encoding systems include ASCII and ASCII-8 .
4- Numbering Systems and Computers
The two primary numbering systems used in conjunction with computers lire binary and decimal. Decimal is translated into binary on input and binary is translated into decimal on output. The hexadecimal numbering system is used primarily as a programmer convenience in reading and reviewing binary output in the form of a memory dump. The octal numbering system has a base of 8.
5- Components of a Computer System: A Closer Look at the Processor and RAM
The processor is the "intelligence" of a computer system. A processor, which is also called the central processing unit or CPU, has only two fundamental sections, the control unit and the arithmetic and logic unit, which work together with RAM to execute programs. The control unit interprets instructions and directs the arithmetic and logic unit to perform computation and logic operations .
RAM, or random-access memory, provides the processor with temporary storage for programs and data. Input/output (I/O) is "read to" or "written from" RAM over a channel. In RAM, datum is stored at a specific address. Most of today’s computers use CMOS technology for RAM. CMOS is volatile memory; that is. the data are lost when the electrical current is turned off or interrupted. In contrast, bubble memory provides nonvolatile memory. All input/output, including programs. must enter and exit RAM. Programs are loaded to RAA from secondary storage in a nondestructive read process. Other variations of internal storage are ROM,PROM, and flash memory.
Some computers employ cache memory to increase throughput. Like RAM. cache is a high-speed holding area for program instructions and data. however cache memory holds only those instructions and data likely to he needed next by the processor. During execution, instructions and data arc passed between very high-speed registers (for example, the instruction register, program register, and the accumulator) in the control unit and the arithmetic logic unit
Every machine language has a predefined formal for each type of instruction. Each instruction has an operation code (op-code) and an operand During one machine cycle, an instruction is "fetched" from RAM, decoded by the decoder in the control unit, executed. and tire results are placed in memory. The machine cycle time is the total of the instruction lime (I-time) and the execution time (E-time).
Most mainframes and PCs use else (complex instruction set computer) architecture Those using RISC (reduced instruction set computer) architecture realize increased throughput for certain applications.
In parallel processing, one main processor examines the programming problem and determines what portions, if any, of the problem can be solved in pieces. Those pieces that can be addressed separately are routed to other processor . solved, then recombined in the main processor to produce the result Parallel processing on a large scale is referred to as massively parallel processing (MPP).
Neural network-designed computers mimic the human mind. When perfected. are expected to excel at human-oriented tasks such as pattern recognition and reading handwriting .
6- Describing the Processor: Distinguishing Characteristics
A processor is described in terms of its word length. speed. and RAM capacity. The word (the number of bits handled as a unit) length of computers ranges from 16 hits for the smaller micros to range bits for more powerful computers. Microcomputer speed is measured in megahertz (MHz). Workstation. mini, and mainframe speed is measured in MIPS. Supercomputer speed is measured in FLOPS and GFLOPS. memory capacity is measured in kilobytes (KB), megabytes (MB), gigabytes (GB). and terabytes (TB). Chip capacity is sometimes stated in kilobits (Kb) and megabits (Mb).
REVIEW EXERCISES
Concepts
1. Distinguish between RAM, ROM and PROM.
2. How many ASCII-S bytes can be stored in a 32-bit word?
3 . Which two functions are performed by the arithmetic and logic unit?
4. List examples of alpha, numeric, and alphanumeric characters.
5. Write your first name as an ASCII hit configuration.
6. What are the functions of the control Unit?
7. we describe computers in terms of what three characteristics ?
8. what are the binary and hexadecimal equivalents of a decimal 12?
9. What is the baste difference between CMOS technology and nonvolatile technology , such as bubble memory?
10. For a given computer. which type of memory would have the greatest capacity to store data and programs: cache or RAM? RAM or registers? registers or cache
11. Name three types of registers
12. Which portion of the fundamental computer purer instruction designates the operation to be performed?
13. Which type of computer architecture has the smaller instruction set, RISC or CISC?
14. The I and the E in I-time and E-time stand for what?
Discussion
15. KB is used to represent 1024 bytes of storage. Would it have been much easier to let KB represent 1000 bytes? Explain.
16. If neural networks realize their potential. the distinction between what have traditionally been human-oriented tasks and machine-oriented tasks may begin to blur. Should society be doing anything that we are not already doing to prepare for this? Explain.
Problem Solving
17. Create a five-bit encoding system to be used for storing uppercase alpha characters, punctuation symbols, and the apostrophe. Discuss the advantages and disadvantages of your encoding system in relation to the ASCII encoding system
18. Compute the time it takes to complete one cycle on a 66-MHz processor in both seconds and nanoseconds.
19. Convert 5 MB to KB, Mb, and Kb. Assume a byte contains eight bits.
20. Complete a numbering-system table that shows the binary, octal, and hexadecimal equivalents for the decimal numbers 1 through 20.
ELF-TEST (by section]
1- Data are stored permanently on secondary storage devices, such as magnetic tape. (T/F)
2- a. Bit is the singular of byte, (T/F)
b. The base of the binary number system is: (a) 2, (b) 8, or (c) 16?
3- The combination of bits used to represent a character is called a –
4- a. A is a "snapshot" of the contents of RAM at a given moment in time.
When you count in hexadecimal, you carry to the next position in groups of
5- a. Data are loaded from secondary to RAM in a nondestructive read process. (T/F)
b. The is that part of the processor that reads and interprets program instructions.
c. The arithmetic and logic unit controls the flow of programs and data In and out of main memory. (T/F)
d. Put the following memories in order based on speed: cache, registers, and RAM,
e. The timed interval that comprises the machine cycle is the total of the time and the time.
6- a. The word length of most microcomputers is 64 bits. (T/F)
b. MIPS is an acronym for "millions of instructions per second." (T/F)
c. is a common measure of super computer processor speed
Self-test answers. 1 T. 2 (a) F; (b) a. 3 byte. 4 (a) memory dump; (b)16.5 (a) T, (b) control unit; (c) F; (d) from the slowest to the fastest memory’ RAM, cache, registers; (e) instruction, execution 6 (a) F; (b) r, (c) FLOPS or GFLOPS.