Card Set Information
How are computers classified?
Technology (mechanical, electromechanical, electronic), purpose (special or general), type of data they handle (analog or digital), cost, physical size (handheld to room size).
Mechanical computers are considered to be of what type?
The Navy uses analog computers primarily for what purpose?
Gun fire control
How do electromechanical computers differ from the mechanical computers?
Electromechanical computers use electrical components to perform some of the calculations.
In electronic computers, vacuum tubes were replaced by transistors and transistors have beenreplaced by what device?
A computer that is designed to perform a specific operation and usually satisfies the needs of aparticular type of problem, is said to be what type of computer?
Rather than using a stored program, a special-purpose computer's applicability to a particular problem is a function of what?
What is a drawback to the special-purpose computer?
Lack of versatility.
A general-purpose computer is designed for what purpose?
To perform a wide variety of functions and operations
How is a general-purpose computer able to perform different operations?
By storing different programs in its internal storage.
In a general-purpose computer, the ability to perform a wide variety of operations is achieved atthe expense of what capabilities?
Speed and efficiency
All analog computers are what type of computers?
What are analog computers designed to measure?
Continuous electrical or physical conditions
Early analog computers were what type of devices?
Mechanical or electromechanical.
What are computers called that combine the functions of both analog and digital computers?
Digital computers are generally used for what purposes?
Business and scientific data processing
What is the fundamental difference between analog and digital computers?
Digital computers deal with discrete quantities, while analog computers deal with continuous
How is the accuracy of an analog computer restricted?
By the accuracy with which physical quantities can be sensed and displayed.
A constant represented by a voltage can be read to what decimal place?
The accuracy of a digital computer is governed by what factor?
The number of significant figures carried in the computations.
In a digital computer, what does the number of decimal places in the constant depend on?
Design of the computer processing unit.
You will most likely be working with what type of computer?
General-purpose digital computer
Technological advancement is measured by what, in the electronic computer world?
What does each generation of computer systems indicate?
Significant change in computer design.
What were computers of the first generation characterized by?
The vacuum tube
How did vacuum tubes cause a problem for first generation computers?
They were unreliable, required a lot of power to run, and produced so much heat that airconditioning was needed to protect computer parts
In first generation computers, internal processing functions were measured by what division of time?
Thousandths of a second (millisecond).
The software (computer program) used on first generation computers was what type?
Unsophisticated and machine oriented
How were processing speed and reliability increased in second generation computers?
By the use of small, long lasting transistors
In second generation computers, how was the storage capacity greatly increased?
With the introduction of magnetic disk storage and the use of core for main storage.
With improvements in software, what kind of computer languages could be used on second generation computers?
Symbolic machine languages or assembly languages.
What do the smaller circuits in third generation computers allow for?
Faster internal processing speeds
On third generation computers, what results are gained by faster internal processing speeds?
Faster execution of instructions
The data cell had a storage capacity of how many characters?
Over 100 million.
What type of applications were most third generation computer systems designed to accomplish?
Both scientific and business data processing applications.
What type of computers are small and inexpensive yet provide a lot of computing power?
Microcomputers and minicomputers.
What does the acronym ROM stand for?
What will be one of the future challenges involving computer power?
How to properly and effectively use the computing power available.
What term is used for programs such as assemblers, compilers, and operating systems?
What is one of the more widespread uses of the computer?
What is the great advantage of computers over typewriters?
How are word processing programs used by the Navy?
For manuscript writing, memorandum writing, identification-card application filing, andrecordkeeping
How many systems dealing with accounting applications have been widely accepted?
What does the acronym S-N-A-P stand for?
Shipboard Non-tactical ADP Program.
For what purposes is the SNAP II system designed?
To support shipboard and intermediate level maintenance, supply, financial, and administrativefunctions.
What does user friendly mean in computer terms?
Operating instructions are written in everyday English.
What does a password prevent?
Unauthorized entry into the main computer's program.
In the SNAP II system, how are the different levels of entry defined?
Dependent on a work center's need.
The work center supervisor can update what items from a user terminal?
COSAL, APL, EIC, SHIP'S FORCE WORK LIST, and CSMP.
At present what type of classified use is allowed for SNAP II?
What is a central set of programs called that manages the execution of other programs andperforms common functions like read, write, and print?
What is the function of a built-in program called a bootstrap loader?
To load an external operating system into the computer's internal memory.
When you see the error message NO SYSTEM, what does it mean?
The computer is reading a properly inserted floppy disk, but it does not have an operating system on it.
When an operating system prompt (A>) is displayed on the screen, what do you enter from thekeyboard to load an application program?
The program name
If disks are stored horizontally, how many can be stacked?
No more than ten.
What can exposure to a magnetic field do to the data on a disk?
Destroy some or all of it
What is the temperature range within which a disk will operate?
10 to 50 degrees Celsius or 50 to 120 degrees Fahrenheit.
What is the most common method to ensure that any stored data lost can be recovered?
The most common method of creating a backup for a microcomputer is what?
Use a floppy disk and the diskcopy procedure
Other than disk, what is another media used for backup files?
What is the brain of a computer system?
The central processing unit
How many sections make up the central processing unit?
What are the names of the sections that make up the cpu?
Control section, internal storage section, and arithmetic-logic section.
The control section can be compared to what?
A telephone exchange
What are the four major types of instructions in the control section?
Transfer, arithmetic, logic, and control
What capability allows the arithmetic/logic section to test various conditions encountered duringprocessing and take action based on the result?
In the arithmetic/logic section, data is returned to what section after processing?
What is the process by which instructions and data are read into a computer?
Magnetic core storage is made up of what?
Tiny doughnut-shaped rings made of ferrite iron.
A semiconductor memory consists of what?
Hundreds of thousands of tiny electronic circuits etched on a silicon chip.
What is another name for semiconductor memory chips?
In computer storage, what does volatile mean?
All data in memory is lost when the power source is removed.
What type of storage can retain its data even if there is a power failure or breakdown?
Nonvolatile (magnetic core storage and bubble memory are examples).
Bubble memory consists of what?
A very thin crystal made of semiconductor material
How are the magnetic domains of a bubble memory switched?
By passing a current through a control circuit imprinted on top of the crystal
What do we mean when we say that reading from bubble memory is nondestructive?
The data is still present after being read
In what type of memory are often used instructions and programs permanently stored inside the
Read-only memory (ROM).
Who provides the programs stored in ROM?
Only the manufacturer
Can programs in ROM be changed?
What is another name for random-access memory (RAM)?
How is data read from or written into RAM?
By giving the computer the address of the location where the data is stored or is to be stored.
In what two states can programmable read-only memory (PROM) be purchased?
Already programmed by the manufacturer or in a blank state.
What is the main disadvantage of PROM?
If a mistake is made and entered, it cannot be corrected or erased.
What does EPROM stand for?
Erasable programmable read-only memory.
How is EPROM erased?
With a burst of ultra-violet light.
Why are disk storage devices popular?
Largely because of their direct access capabilities.
How is data stored on all disks?
In a number of invisible concentric circles called tracks
What precedes each record on a disk?
A disk address
How is the storage capacity of a disk determined?
By the bits per inch of track and the tracks per inch of surface.
What two ways can data be physically organized on a disk pack?
By cylinder or sector.
The amount of data that can be stored on a linear inch of tape is known by what term?
The length of tape between BOT and EOT is referred to by what term?
The usable recording (reading/writing) surface or usable storage area.
How does a magnetic drum differ from a magnetic disk?
The tracks in which the data is stored are assigned to channels that form circular bands aroundthe drum.
Tracks on each channel of a magnetic drum are grouped into what?
What is the purpose of any magnetic tape unit?
To write data on or read data from a magnetic tape.
What are the major differences between magnetic tape units?
The speed at which the tape is moved past the read/write head and the density of the recorded information.
Why is direct accessing of data a big advantage over the sequential accessing of data?
It gives us fast, immediate access to specific data without having to examine each and every record from the beginning.
What is a floppy disk?
A thin, flexible platter coated with magnetic material so characters can be recorded.
What are the three most common sizes of floppy disks?
8 inch, 5 1/4 inch, and 3 1/2 inch
What output device expresses coded characters as hard copy (paper documents)?
What four types of printers are commonly used with personal computers?
Daisy-wheel, dot-matrix, ink jet, and laser.
What is the primary purpose of a keyboard?
To enter or input alphanumeric character codes
Raster scan or tv scan video monitors are used extensively for what purpose?
The display of alphanumeric data and graphics.
How many fields make up a frame?
A field is approximately how many horizontal lines?
What are picture elements often called?
Pixels or pels
Vertical resolution depends on what?
The number of horizontal scan lines used.
Flat panel displays are designed to reduce what problem of a crt display?
Reduce the depth of the crt display caused by the length of the tube
What does the liquid crystal display require for computer applications?
An external light source, called a backlight
What is the heart of any computer system?
The operating system
Which types of operating systems are the simplest and most common on microcomputers?
Single user/single tasking.
What types of operating systems let more than one user access the same resources at the same time?
Why is the availability of applications software for a particular operating system critical?
Because, to use applications software, it must be compatible with the operating system.
How is the applications software compatibility problem overcome?
Some software comes in several versions so it can run under several different operating systems
What programs eliminate the need for programmers to write new programs when all they want to do is copy, print, or sort a data file?
How do we tell a utility program what we want it to do?
By providing information about files, data fields, and the process to be used.
What is the term given to arranging data records in a predefined sequence or order?
To sort a data file, what must you tell the sort program?
What data field or fields to sort on.
What are report program generators used for?
To generate programs to print detail and summary reports of data files.
With early computers, the programmer had to translate instructions into what type of language form?
When were mnemonic instruction codes and symbolic addresses developed?
In the early 1950's
What led to the development of procedure oriented languages?
The development of mnemonic techniques and macroinstructions.
What computer language was developed for mathematical work?
What are two disadvantages of procedure oriented languages?
They require more space in memory and they process data at a slower rate than symbolic languages.
What is programming?
The process of planning the solution to a problem
In programming, how many steps are involved in solving a problem on a computer?
What is required before you can actually start to write or code a program?
In flowcharting, what method is used to represent different operations, data flow, equipment, andso forth?
Different shaped symbols.
What type of flowchart is constructed by the programmer to represent the sequence of operations the computer is to perform to solve a specific problem?
A programming flowchart
How many tools are used in flow charting?
Is there a "best way" to construct a flowchart?
No, there isn't a way to standardize problem solution.
What controls the computer during processing?
What is the fundamental element in program preparation?
What type of instructions permit addition, subtraction, multiplication, and division?
Where is specific information about the computer you are to use contained?
In the computer manufacturers or software designers user's manual.
How do we refer to errors caused by faulty logic and coding mistakes?
What is the purpose of testing a program?
To determine that all data can be processed correctly and that the output is correct.
What is packaged software?
Off-the-shelf programs designed for specific classes of applications.
What are some of the other features and software available with a word processing software package?
Spelling checkers, mailing list programs, document compilation programs, and communications programs.
What software allows you to enter data and then retrieve it in a variety of ways?
What are spreadsheets?
They are tables of rows and columns of numbers.
Are all printers capable of handling graphics output?