TyroCity: Computer 11 Notes

Primary Memory

Computer 11 Notes — Sun, 08 Apr 2012 05:41:42 +0000

It is also known as Main memory/System memory/Internal memory. It is a semi-conductor memory. It is used for storing data, programs while they are being used in a computer. It is the only memory which is directly accessible to CPU. It is usually faster for read/write, expensive and used in smaller capacity compared to secondary memory. The different primary memory used are:

1. RAM
It stands for Random Access Memory. It is a read/write memory. It is volatile memory i.e. the stored data will be lost after the computer is turned off. It is used for storing data and instructions while they are being processed by CPU, waiting to be processed and the result after processing before it is provided to output device. Types of RAM are:

- S-RAM (Static-random access memory)
In this RAM the stored data will not be lost till the computer is in “on” state. It is expensive but faster for read/write than D-RAM.

- D-RAM (Dynamic-random access memory)
In this RAM the stored data will be lost after a few milliseconds even if the computer is in “on” state. So, to prevent data loss refreshing circuit is required. It is cheaper but slower for read/write than S-RAM.

2. ROM
It stands for Read Only Memory. It is non-volatile memory i.e. the stored programs will not be lost after the computer is turned “off”. It is used for storing programs required for operating electronic devices. It is usually cheaper and used in smaller storage capacity than RAM. Types of ROM are:

P-ROM (Programmable-read only memory)
It is a blank ROM in which programs can be stored once, after storing program it is converted into read only then erasing or updating is not possible. ROM burner is used for storing program in it.
EP-ROM (Erasable programmable-read only memory)
It can be erased by exposing it to the UV rays for about 20-25 minutes. While erasing the complete block will be erased and bit by bit erasing is not possible. It is more flexible but expensive than P-ROM.
EEP-ROM (Electronically erasable programmable-read only memory)
It can be erased by using electronic circuit. Bit by bit erasing is possible so, it is even more flexible but expensive than EP-ROM. Flash memory like memory chip, pen drive are the modification of EEP-ROM.

S-RAM	D-RAM
It stands for Static-Random Access Memory.	It stands for Dynamic-Random Access Memory.
In this RAM the stores data will be lost only after the computer is turned off.	In this RAM the stored data will be lost after few millisecond even if the computer is in “on” state.
It doesn’t require refreshing circuit.	It requires refreshing circuit.
It is faster for read/write.	It is slower for read/write.
It stores data in form of voltage.	It stores data in form of charge.
A single memory cell of S-RAM is made by 6 transistors and an electronic circuit.	A single memory cell of D-RAM is made by 1 transistor and 1 capacitor.
It is expensive.	It is cheaper.
The memory cells are larger in size and are loosely packed.	The memory cells are smaller in size and are tightly packed.
It is rarely used in PC at present.	It is widely used in PC at present.

Cache memory

Cache memory is a high speed memory placed in between CPU and RAM. It is used for increasing the overall operating speed of the computer. It balances the difference in operating speed of RAM and CPU. It is 5-10 times faster than RAM. It stores data and instructions which are frequently required by CPU. When CPU requires any data it searches the data in Cache and if not found it searches in RAM. The condition in which CPU finds data in Cache is known as hit and if not found the condition is known as miss. The ratio of hit and miss in present computer is 9:1. Cache is further divided into L1 Cache and L2 Cache. L1 Cache contains more frequently required data compared to L2 Cache.

Position of cache memory

Programming Concept | Computer Science | HSEB Notes

Computer 11 Notes — Sun, 08 Apr 2012 05:41:42 +0000

Detailed notes to follow:

- Types of programming language

1. Low level language

Machine Language (1GL)
Assembly Language (2GL)

2. High level language

Procedural-Oriented Language (3GL)
Problem-Oriented (Fourth Generation) Language (4GL)
Natural (Fifth Generation) Language (5GL)

- Language translator

Assembler
Compiler
Interpreter

- Syntax and semetics

Syntax Error
Sematic Error
Run-Time Error

- Flowchart

System Flowchart
Program Flowchart

Mail Merge

Computer 11 Notes — Sun, 08 Apr 2012 05:41:42 +0000

Introduction to mail merge
The Mail Merge feature has been described here. In Ms-Word Mail Merge option is an important and every way for office set up. Many times we required sending the same content of a letter to different individuals. By using Mail Merge you can send the same letter to a number of persons without typing the content of the letter again and again.

Objectives
At the end of the lesson you should be able to:

understand the concept of Mail Merge
create a main document
create a data source
link the main document with the data source
merge print a document

What is mail merge?
In any working environment, there are situations when a similar type of letter or document is to be sent to many persons who reside at different locations. The letters may contain the address of each recipient, in addition to the standard information contained in the letter. One way of doing this is to print the letters by changing the address each time in the document after printing such letter. But this would mean lot of effort and time and also results in bad organisation.
Such problems are taken care of by the Mail Merge facility. In word processing, Mail Merge is the process of transferring selected information from one document to another document.

Concept of mail merging and its components
Mail Merge is the facility which requires the following three information

General body of the letter called main document
Header Row, the record structure or the name of the fields, which will identify the data
Data for all the individuals, for whom the letters are to be generated also called data source

Mail Merge option of Word reads this data and physically merges it with Main document to generate letters for all the persons or for all records in the data file.
Main Document
Data Source

- Main document
In Mail Merge, Main Document is the common letter, which contains the common information for each of the merged document. It also contains the field names, which contain the instructions for carrying out the merge.

- Data source
Data Source is also called the Data File. It stores information to be brought into the Main document. The data file table contains a column for each category of information, or data field, in the data file. The Header Row is the first row of the table. It contains field names, which indicate the type of information in each column. For example list of names and addresses.
Each field name must be unique and must begin with an alphabet/letter.

- Form letter
Form letter is the resultant document of the mail merge operations, which contains the copy of the main document along with each piece of information stored in the data file.

In-text questions 1

What do you mean by Mail Merge?
What are the three information required for Mail Merge?
Define Form Letter.

Mail merge option of word
Thus by now it is clear that for Mail Merge document, you need to

Create the main document
Create data source
Merge the data with document

All these operations can be performed by Mail Merge option of WORD. In order to invoke the Mail Merge option, choose the Mail Merge option of the Tools menu. The following Mail Merge Helper box will appear.
Mail Merge helper guides you through the steps of mail merging a document. There are three main options available in the box.

- Creating the Main document
The first step in the mail merge is to create the main document. For this, choose ‘Create’ button of ‘Main Document’ option in Mail Merge Helper box. The following menu will be displayed

Form Letter…
Mailing Labels…
Envelopes…
Catalog…
Restore to Normal Word document Now choose ‘form letters’ option from this menu as the type of main document. The following box will appear. Choose the Active Window button from the above box. Type the main document and again invoke the Mail Merge Helper.

- Creating data source
Choose the ‘get data’ button from the Mail Merge Helper box. For creating data source, select Create Data Source. The following dialog box will appear.
The field names are already available in the Header row, which are default fields for an address list. Any field that is not required can be removed, and any new field can be added. For removing a field, highlight that particular field and click on the ‘Remove field Name’ button. For adding a new field, type the name of the field in the Field Name box and then click on the ‘Add Field Name’ button.
Click on the ok button and save your data structure as well as the data source. The following dialog box will appear.
Click on the ‘edit data source’ button from the box to enter records in the data file. A Data Form dialog box will be displayed.
Enter the records by typing in the boxes. For adding a record choose ‘add new’ button. For removing a record, choose ‘delete’ button. After you finish with adding records, click on the ok button.

- Opening the data source
You can also use a data source already created. You can open it by clicking the ‘get data’ option in the Mail Merge Helper and then selecting ‘Open Data Source’ A dialog box will appear with a list of data source file names. Select the name of the data source to open it.

- Merging the text with data
After creating the main document and data source, the third step is to merge the main document with the data source. For this, invoke the Mail Merge Helper again and choose the ‘merge’ button. The following dialog box will appear.

Select ‘new document’ from the ‘merge to’ drop-down list and click on ‘merge’ button. The form letters are generated and stored in the document which may be previewed for final adjustment in the main document, before printing the for letters.

Merge printing
You can directly print the Form Letters without previewing them. Select the Printer option, then the form letters are directly printed on the printer.

Conditional merging
You can also mail merge the document with a condition. There are two options available in the Merge dialog box i.e., ‘Merge’ and ‘Query Options’ options. Using Query Option’ you can define the selection criteria so that at the time of merging only those records are selected which meet the defined selection criteria.

In-text questions 2

1. State whether the following statement is True or False.

For mail merge document, you need to create the main document.
To create Data Source choose the get data button from the mail merge helper box.
For adding new field, type the name of the field in record name box.
After creating the main document and data source, the third step is to merge main document with the data source.
You can directly print the form letters without previewing them.
Merge and query are two options available in merge dialog box.

What you have learnt
After going through this lesson you have learnt the concept of mail merge and its usefulness. The mail merge feature of Ms-Word requires mainly two components: the main document and the data file. The main document is the body of the letter that has to be sent. The data file contains the list of names and addresses in the form of fields. You have learnt the procedures of creating the main document and the data file, and combining them.

Terminal questions

What do you understand by Mail Merge?
Define the different components of Mail Merge.
How do you invoke ‘Mail Merge Helper’ window?
Differentiate between Merge and Query option of ‘Mail Merge Helper’ window.

Feedback to in-text questions

In-text question 1

The process of transferring selected information from one document to another document is known as Mail Merge.
Main Document, Data Source and Form Letter.
Form letter is the resultant document of the mail merge operations, which contains the copy of the main document along with each piece of information stored in the data file.

In-text question 2

True
True
False
True
False
True

MS Excel Functions

Computer 11 Notes — Sun, 08 Apr 2012 05:41:42 +0000

The following sections list all of the worksheet functions by category.

Database functions
Function Description
DAVERAGE- Returns the average of selected database entries
DCOUNT- Counts the cells that contain numbers in a database
DCOUNTA- Counts nonblank cells in a database
DGET- Extracts from a database a single record that matches the specified criteria
DMAX- Returns the maximum value from selected database entries
DMIN- Returns the minimum value from selected database entries
DPRODUCT- Multiplies the values in a particular field of records that match the criteria in a database
DSTDEV- Estimates the standard deviation based on a sample of selected database entries
DSTDEVP- Calculates the standard deviation based on the entire population of selected database entries
DSUM- Adds the numbers in the field column of records in the database that match the criteria
DVAR- Estimates variance based on a sample from selected database entries
DVARP- Calculates variance based on the entire population of selected database entries

Date and time functions
Function Description
DATE- Returns the serial number of a particular date
DATEVALUE- Converts a date in the form of text to a serial number
DAY- Converts a serial number to a day of the month
DAYS360- Calculates the number of days between two dates based on a 360-day year
EDATE- Returns the serial number of the date that is the indicated number of months before or after the start date
EOMONTH- Returns the serial number of the last day of the month before or after a specified number of months
HOUR- Converts a serial number to an hour
MINUTE- Converts a serial number to a minute
MONTH- Converts a serial number to a month
NETWORKDAYS- Returns the number of whole workdays between two dates
NOW- Returns the serial number of the current date and time
SECOND- Converts a serial number to a second
TIME- Returns the serial number of a particular time
TIMEVALUE- Converts a time in the form of text to a serial number
TODAY- Returns the serial number of today’s date
WEEKDAY- Converts a serial number to a day of the week
WEEKNUM- Converts a serial number to a number representing where the week falls numerically with a year
WORKDAY- Returns the serial number of the date before or after a specified number of workdays
YEAR- Converts a serial number to a year
YEARFRAC- Returns the year fraction representing the number of whole days between start_date and end_date

Engineering functions
Function Description
BESSELI- Returns the modified Bessel function In(x)
BESSELJ- Returns the Bessel function Jn(x)
BESSELK- Returns the modified Bessel function Kn(x)
BESSELY- Returns the Bessel function Yn(x)
BIN2DEC- Converts a binary number to decimal
BIN2HEX- Converts a binary number to hexadecimal
BIN2OCT- Converts a binary number to octal
COMPLEX- Converts real and imaginary coefficients into a complex number
CONVERT- Converts a number from one measurement system to another
DEC2BIN- Converts a decimal number to binary
DEC2HEX- Converts a decimal number to hexadecimal
DEC2OCT- Converts a decimal number to octal
DELTA- Tests whether two values are equal
ERF- Returns the error function
ERFC- Returns the complementary error function
GESTEP- Tests whether a number is greater than a threshold value
HEX2BIN- Converts a hexadecimal number to binary
HEX2DEC- Converts a hexadecimal number to decimal
HEX2OCT- Converts a hexadecimal number to octal
IMABS- Returns the absolute value (modulus) of a complex number
IMAGINARY- Returns the imaginary coefficient of a complex number
IMARGUMENT- Returns the argument theta, an angle expressed in radians
IMCONJUGATE- Returns the complex conjugate of a complex number
IMCOS- Returns the cosine of a complex number
IMDIV- Returns the quotient of two complex numbers
IMEXP- Returns the exponential of a complex number
IMLN- Returns the natural logarithm of a complex number
IMLOG10- Returns the base-10 logarithm of a complex number
IMLOG2- Returns the base-2 logarithm of a complex number
IMPOWER- Returns a complex number raised to an integer power
IMPRODUCT- Returns the product of from 2 to 29 complex numbers
IMREAL- Returns the real coefficient of a complex number
IMSIN- Returns the sine of a complex number
IMSQRT- Returns the square root of a complex number
IMSUB- Returns the difference between two complex numbers
IMSUM- Returns the sum of complex numbers
OCT2BIN- Converts an octal number to binary
OCT2DEC- Converts an octal number to decimal
OCT2HEX- Converts an octal number to hexadecimal

Financial functions
Function Description
ACCRINT- Returns the accrued interest for a security that pays periodic interest
ACCRINTM- Returns the accrued interest for a security that pays interest at maturity
AMORDEGRC- Returns the depreciation for each accounting period by using a depreciation coefficient
AMORLINC- Returns the depreciation for each accounting period
COUPDAYBS- Returns the number of days from the beginning of the coupon period to the settlement date
COUPDAYS- Returns the number of days in the coupon period that contains the settlement date
COUPDAYSNC- Returns the number of days from the settlement date to the next coupon date
COUPNCD- Returns the next coupon date after the settlement date
COUPNUM- Returns the number of coupons payable between the settlement date and maturity date
COUPPCD- Returns the previous coupon date before the settlement date
CUMIPMT- Returns the cumulative interest paid between two periods
CUMPRINC- Returns the cumulative principal paid on a loan between two periods
DB- Returns the depreciation of an asset for a specified period by using the fixed-declining balance method
DDB- Returns the depreciation of an asset for a specified period by using the double-declining balance method or some other method that you specify
DISC- Returns the discount rate for a security
DOLLARDE- Converts a dollar price, expressed as a fraction, into a dollar price, expressed as a decimal number
DOLLARFR- Converts a dollar price, expressed as a decimal number, into a dollar price, expressed as a fraction
DURATION- Returns the annual duration of a security with periodic interest payments
EFFECT- Returns the effective annual interest rate
FV- Returns the future value of an investment
FVSCHEDULE- Returns the future value of an initial principal after applying a series of compound interest rates
INTRATE- Returns the interest rate for a fully invested security
IPMT- Returns the interest payment for an investment for a given period
IRR- Returns the internal rate of return for a series of cash flows
ISPMT- Calculates the interest paid during a specific period of an investment
MDURATION- Returns the Macauley modified duration for a security with an assumed par value of $100
MIRR- Returns the internal rate of return where positive and negative cash flows are financed at different rates
NOMINAL- Returns the annual nominal interest rate
NPER- Returns the number of periods for an investment
NPV- Returns the net present value of an investment based on a series of periodic cash flows and a discount rate
ODDFPRICE- Returns the price per $100 face value of a security with an odd first period
ODDFYIELD- Returns the yield of a security with an odd first period
ODDLPRICE- Returns the price per $100 face value of a security with an odd last period
ODDLYIELD- Returns the yield of a security with an odd last period
PMT- Returns the periodic payment for an annuity
PPMT- Returns the payment on the principal for an investment for a given period
PRICE- Returns the price per $100 face value of a security that pays periodic interest
PRICEDISC- Returns the price per $100 face value of a discounted security
PRICEMAT- Returns the price per $100 face value of a security that pays interest at maturity
PV- Returns the present value of an investment
RATE- Returns the interest rate per period of an annuity
RECEIVED- Returns the amount received at maturity for a fully invested security
SLN- Returns the straight-line depreciation of an asset for one period
SYD- Returns the sum-of-years’ digits depreciation of an asset for a specified period
TBILLEQ- Returns the bond-equivalent yield for a Treasury bill
TBILLPRICE- Returns the price per $100 face value for a Treasury bill
TBILLYIELD- Returns the yield for a Treasury bill
VDB- Returns the depreciation of an asset for a specified or partial period by using a declining balance method
XIRR- Returns the internal rate of return for a schedule of cash flows that is not necessarily periodic
XNPV- Returns the net present value for a schedule of cash flows that is not necessarily periodic
YIELD- Returns the yield on a security that pays periodic interest
YIELDDISC- Returns the annual yield for a discounted security; for example, a Treasury bill
YIELDMAT- Returns the annual yield of a security that pays interest at maturity

Information functions
Function Description
CELL- Returns information about the formatting, location, or contents of a cell
ERROR.TYPE- Returns a number corresponding to an error type
INFO- Returns information about the current operating environment
ISBLANK- Returns TRUE if the value is blank
ISERR- Returns TRUE if the value is any error value except #N/A
ISERROR- Returns TRUE if the value is any error value
ISEVEN- Returns TRUE if the number is even
ISLOGICAL- Returns TRUE if the value is a logical value
ISNA- Returns TRUE if the value is the #N/A error value
ISNONTEXT- Returns TRUE if the value is not text
ISNUMBER- Returns TRUE if the value is a number
ISODD- Returns TRUE if the number is odd
ISREF- Returns TRUE if the value is a reference
ISTEXT- Returns TRUE if the value is text
N- Returns a value converted to a number
NA- Returns the error value #N/A
TYPE- Returns a number indicating the data type of a value

Logical functions
Function Description
AND- Returns TRUE if all of its arguments are TRUE
FALSE- Returns the logical value FALSE
IF- Specifies a logical test to perform
NOT- Reverses the logic of its argument
OR- Returns TRUE if any argument is TRUE
TRUE- Returns the logical value TRUE

Lookup and reference functions
Function Description
ADDRESS- Returns a reference as text to a single cell in a worksheet
AREAS- Returns the number of areas in a reference
CHOOSE- Chooses a value from a list of values
COLUMN- Returns the column number of a reference
COLUMNS- Returns the number of columns in a reference
GETPIVOTDATA- Returns data stored in a PivotTable
HLOOKUP- Looks in the top row of an array and returns the value of the indicated cell
HYPERLINK- Creates a shortcut or jump that opens a document stored on a network server, an intranet, or the Internet
INDEX- Uses an index to choose a value from a reference or array
INDIRECT- Returns a reference indicated by a text value
LOOKUP- Looks up values in a vector or array
MATCH- Looks up values in a reference or array
OFFSET- Returns a reference offset from a given reference
ROW- Returns the row number of a reference
ROWS- Returns the number of rows in a reference
RTD- Retrieves real-time data from a program that supports COM automation(Automation: A way to work with an application’s objects from another application or development tool. Formerly called OLE Automation, Automation is an industry standard and a feature of the Component Object Model (COM).)
TRANSPOSE- Returns the transpose of an array
VLOOKUP- Looks in the first column of an array and moves across the row to return the value of a cell

Math and trigonometry functions
Function Description
ABS- Returns the absolute value of a number
ACOS- Returns the arccosine of a number
ACOSH- Returns the inverse hyperbolic cosine of a number
ASIN- Returns the arcsine of a number
ASINH- Returns the inverse hyperbolic sine of a number
ATAN- Returns the arctangent of a number
ATAN2- Returns the arctangent from x- and y-coordinates
ATANH- Returns the inverse hyperbolic tangent of a number
CEILING- Rounds a number to the nearest integer or to the nearest multiple of significance
COMBIN Returns the number of combinations for a given number of objects
COS- Returns the cosine of a number
COSH- Returns the hyperbolic cosine of a number
DEGREES- Converts radians to degrees
EVEN- Rounds a number up to the nearest even integer
EXP- Returns e raised to the power of a given number
FACT- Returns the factorial of a number
FACTDOUBLE- Returns the double factorial of a number
FLOOR- Rounds a number down, toward zero
GCD- Returns the greatest common divisor
INT- Rounds a number down to the nearest integer
LCM- Returns the least common multiple
LN- Returns the natural logarithm of a number
LOG- Returns the logarithm of a number to a specified base
LOG10- Returns the base-10 logarithm of a number
MDETERM- Returns the matrix determinant of an array
MINVERSE- Returns the matrix inverse of an array
MMULT- Returns the matrix product of two arrays
MOD- Returns the remainder from division
MROUND- Returns a number rounded to the desired multiple
MULTINOMIAL- Returns the multinomial of a set of numbers
ODD- Rounds a number up to the nearest odd integer
PI- Returns the value of pi
POWER- Returns the result of a number raised to a power
PRODUCT- Multiplies its arguments
QUOTIENT- Returns the integer portion of a division
RADIANS- Converts degrees to radians
RAND- Returns a random number between 0 and 1
RANDBETWEEN- Returns a random number between the numbers you specify
ROMAN- Converts an arabic numeral to roman, as text
ROUND- Rounds a number to a specified number of digits
ROUNDDOWN- Rounds a number down, toward zero
ROUNDUP- Rounds a number up, away from zero
SERIESSUM- Returns the sum of a power series based on the formula
SIGN- Returns the sign of a number
SIN- Returns the sine of the given angle
SINH- Returns the hyperbolic sine of a number
SQRT- Returns a positive square root
SQRTPI- Returns the square root of (number * pi)
SUBTOTAL- Returns a subtotal in a list or database
SUM- Adds its arguments
SUMIF- Adds the cells specified by a given criteria
SUMPRODUCT- Returns the sum of the products of corresponding array components
SUMSQ- Returns the sum of the squares of the arguments
SUMX2MY2- Returns the sum of the difference of squares of corresponding values in two arrays
SUMX2PY2- Returns the sum of the sum of squares of corresponding values in two arrays
SUMXMY2- Returns the sum of squares of differences of corresponding values in two arrays
TAN- Returns the tangent of a number
TANH- Returns the hyperbolic tangent of a number
TRUNC- Truncates a number to an integer

Statistical functions
Function Description
AVEDEV- Returns the average of the absolute deviations of data points from their mean
AVERAGE- Returns the average of its arguments
AVERAGEA- Returns the average of its arguments, including numbers, text, and logical values
BETADIST- Returns the beta cumulative distribution function
BETAINV- Returns the inverse of the cumulative distribution function for a specified beta distribution
BINOMDIST- Returns the individual term binomial distribution probability
CHIDIST- Returns the one-tailed probability of the chi-squared distribution
CHIINV- Returns the inverse of the one-tailed probability of the chi-squared distribution
CHITEST- Returns the test for independence
CONFIDENCE- Returns the confidence interval for a population mean
CORREL- Returns the correlation coefficient between two data sets
COUNT- Counts how many numbers are in the list of arguments
COUNTA- Counts how many values are in the list of arguments
COUNTBLANK- Counts the number of blank cells within a range
COUNTIF- Counts the number of nonblank cells within a range that meet the given criteria
COVAR- Returns covariance, the average of the products of paired deviations
CRITBINOM- Returns the smallest value for which the cumulative binomial distribution is less than or equal to a criterion value
DEVSQ- Returns the sum of squares of deviations
EXPONDIST- Returns the exponential distribution
FDIST- Returns the F probability distribution
FINV- Returns the inverse of the F probability distribution
FISHER- Returns the Fisher transformation
FISHERINV- Returns the inverse of the Fisher transformation
FORECAST- Returns a value along a linear trend
FREQUENCY- Returns a frequency distribution as a vertical array
FTEST- Returns the result of an F-test
GAMMADIST- Returns the gamma distribution
GAMMAINV- Returns the inverse of the gamma cumulative distribution
GAMMALN- Returns the natural logarithm of the gamma function, Γ(x)
GEOMEAN- Returns the geometric mean
GROWTH- Returns values along an exponential trend
HARMEAN- Returns the harmonic mean
HYPGEOMDIST- Returns the hypergeometric distribution
INTERCEPT- Returns the intercept of the linear regression line
KURT- Returns the kurtosis of a data set
LARGE- Returns the k-th largest value in a data set
LINEST- Returns the parameters of a linear trend
LOGEST- Returns the parameters of an exponential trend
LOGINV- Returns the inverse of the lognormal distribution
LOGNORMDIST- Returns the cumulative lognormal distribution
MAX- Returns the maximum value in a list of arguments
MAXA- Returns the maximum value in a list of arguments, including numbers, text, and logical values
MEDIAN- Returns the median of the given numbers
MIN- Returns the minimum value in a list of arguments
MINA- Returns the smallest value in a list of arguments, including numbers, text, and logical values
MODE- Returns the most common value in a data set
NEGBINOMDIST- Returns the negative binomial distribution
NORMDIST- Returns the normal cumulative distribution
NORMINV- Returns the inverse of the normal cumulative distribution
NORMSDIST- Returns the standard normal cumulative distribution
NORMSINV- Returns the inverse of the standard normal cumulative distribution
PEARSON- Returns the Pearson product moment correlation coefficient
PERCENTILE- Returns the k-th percentile of values in a range
PERCENTRANK- Returns the percentage rank of a value in a data set
PERMUT- Returns the number of permutations for a given number of objects
POISSON- Returns the Poisson distribution
PROB- Returns the probability that values in a range are between two limits
QUARTILE- Returns the quartile of a data set
RANK- Returns the rank of a number in a list of numbers
RSQ- Returns the square of the Pearson product moment correlation coefficient
SKEW- Returns the skewness of a distribution
SLOPE- Returns the slope of the linear regression line
SMALL- Returns the k-th smallest value in a data set
STANDARDIZE- Returns a normalized value
STDEV- Estimates standard deviation based on a sample
STDEVA- Estimates standard deviation based on a sample, including numbers, text, and logical values
STDEVP- Calculates standard deviation based on the entire population
STDEVPA- Calculates standard deviation based on the entire population, including numbers, text, and logical values
STEYX- Returns the standard error of the predicted y-value for each x in the regression
TDIST- Returns the Student’s t-distribution
TINV- Returns the inverse of the Student’s t-distribution
TREND- Returns values along a linear trend
TRIMMEAN- Returns the mean of the interior of a data set
TTEST- Returns the probability associated with a Student’s t-test
VAR- Estimates variance based on a sample
VARA- Estimates variance based on a sample, including numbers, text, and logical values
VARP- Calculates variance based on the entire population
VARPA- Calculates variance based on the entire population, including numbers, text, and logical values
WEIBULL Returns the Weibull distribution
ZTEST- Returns the one-tailed probability-value of a z-test

Text functions
REPLACE, REPLACEB
Function Description
ASC- Changes full-width (double-byte) English letters or katakana within a character string to half-width (single-byte) characters
BAHTTEXT- Converts a number to text, using the ß (baht) currency format
CHAR- Returns the character specified by the code number
CLEAN- Removes all nonprintable characters from text
CODE- Returns a numeric code for the first character in a text string
CONCATENATE- Joins several text items into one text item
DOLLAR- Converts a number to text, using the $ (dollar) currency format
EXACT- Checks to see if two text values are identical
FIND, FINDB- Finds one text value within another (case-sensitive)
FIXED- Formats a number as text with a fixed number of decimals
JIS- Changes half-width (single-byte) English letters or katakana within a character string to full-width (double-byte) characters
LEFT, LEFTB- Returns the leftmost characters from a text value
LEN, LENB- Returns the number of characters in a text string
LOWER Converts text to lowercase
MID, MIDB- Returns a specific number of characters from a text string starting at the position you specify
PHONETIC- Extracts the phonetic (furigana) characters from a text string
PROPER- Capitalizes the first letter in each word of a text value
Replaces characters within text
REPT- Repeats text a given number of times
RIGHT, RIGHTB- Returns the rightmost characters from a text value
SEARCH, SEARCHB- Finds one text value within another (not case-sensitive)
SUBSTITUTE- Substitutes new text for old text in a text string
T- Converts its arguments to text
TEXT- Formats a number and converts it to text
TRIM- Removes spaces from text
UPPER- Converts text to uppercase
VALUE- Converts a text argument to a number

External functions
Function Description
EUROCONVERT- Converts a number to euros, converts a number from euros to a euro member currency, or converts a number from one euro member currency to another by using the euro as an intermediary (triangulation)
SQL.REQUEST- Connects with an external data source and runs a query from a worksheet, then returns the result as an array without the need for macro programming

Application Package | Computer Science | HSEB Notes

Computer 11 Notes — Sun, 08 Apr 2012 05:41:42 +0000

Detailed notes to follow:

1. Word processor

Use & Character
Examples
Some Important Terms Used: Thesaurus, speller, mail merge

2. Spread sheet

Use & Character
Examples
Some Important Terms Used: Relative cell reference, absolute cell reference

3. Presentation

Use & Character
Examples

SPOOL (Simultaneous Peripheral Operation On-line)

Computer 11 Notes — Sun, 08 Apr 2012 05:41:42 +0000

It is a free space of secondary memory managed by OS for the communication with peripheral devices like printer. It is required because of the difference in the operating speed of the CPU and peripheral devices. Peripheral devices are slow in their operation. The process of using SPOOL is known as spooling.

Introduction To Computer

Computer 11 Notes — Sun, 08 Apr 2012 05:41:42 +0000

- Characteristics/Features of Computer

Speed
Accuracy
Reliability
Storage Capacity
Word Length
Diligence
Versatile
Automatic
Electronic
Non-intelligent

- Application Areas of Computer

Education
Communication
Business
Transportation
Banking
Helth
Security
Industry
Scientific Research
Entertainment
Weather Forecasting
Desktop Publishing
Designing
Satellite Controlling

- Aviation

Capabilities & Limitations of Computer
Advantages & disadvantages of Computer
History of Computer

- Mechanical Age

Abacus
Stepped Reckoner (Leibniz Calculator)
Napier Bone
Difference Engine
Slide Rule
Analytical Engine
Pascaline
Tabulating Machine

- Electro Mechanical Age

MARK-I [Also known as ASCC (Automated Sequence Controlled Calculator)
MARK-II
ABC (Atanasoft Berry Computer)

- Electric Age

ENIAC
EDAC
EDVAC
UNIVAC

Some Important Persons
o Joseph Jaquard
o Charles Babbage
o George Boole
o Herman Hollerith
o Lady Augusta Ada Lovelace

Language/Software

Computer 11 Notes — Sun, 08 Apr 2012 05:41:42 +0000

Introduction

In the previous lesson we discussed about the different parts and configurations of computer. It has been mentioned that programs or instructions have to be fed to the computer to do specific task. So it is necessary to provide sequence of instructions so that your work can be done. We can divide the computer components into two major areas, namely, hardware and software. Hardware is the machine itself and its various individual equipment. It includes all mechanical, electronic and magnetic devices such as monitor, printer, electronic circuit, floppy and hard disk. In this lesson we will discuss about the other part, namely, software.

Objectives

After going through this lesson you will be able to

explain the concept of software
distinguish between different types of software
differentiate application software from system software
define a language
differentiate between different types of language
distinguish between compiler and interpreter

What is software?

As you know computer cannot do anything without instructions from the user. In order to do any specific job you have to give a sequence of instructions to the computer. This set of instructions is called a computer program. Software refers to the set of computer programs, procedures that describe the programs, how they are to be used. We can say that it is the collection of programs, which increase the capabilities of the hardware. Software guides the computer at every step where to start and stop during a particular job. The process of software development is called programming.

You should keep in mind that software and hardware are complementary to each other. Both have to work together to produce meaningful result. Another important point you should know that producing software is difficult and expensive.

Software types

Computer software is normally classified into two broad categories.

Application Software
System software

Application software: Application Software is a set of programs to carry out operations for a specific application. For example, payroll is an application software for an organization to produce pay slips as an output. Application software is useful for word processing, billing system, accounting, producing statistical report, analysis of numerous data in research, weather forecasting, etc. In later modules you will learn about MS WORD, Lotus 1-2-3 and dBASE III Plus. All these are application software.

Another example of application software is programming language. Among the programming languages COBOL (Common Business Oriented Language) is more suitable for business application whereas FORTRAN (Formula Translation) is useful for scientific application. We will discuss about languages in next section.

System software: You know that an instruction is a set of programs that has to be fed to the computer for operation of computer system as a whole. When you switch on the computer the programs written in ROM is executed which activates different units of your computer and makes it ready for you to work on it. This set of program can be called system software. Therefore system software may be defined as a set of one or more programs designed to control the operation of computer system.

System software are general programs designed for performing tasks such as controlling all operations required to move data into and out of the computer. It communicates with printers, card reader, disk, tapes etc. monitor the use of various hardware like memory, CPU etc. Also system software are essential for the development of applications software. System Software allows application packages to be run on the computer with less time and effort. Remember that it is not possible to run application software without system software.

Development of system software is a complex task and it requires extensive knowledge of computer technology. Due to its complexity it is not developed in house. Computer manufactures build and supply this system software with the computer system. DOS, UNIX and WINDOWS are some of the widely used system software. Out of these UNIX is a multi-user operating system whereas DOS and WINDOWS are PC-based. We will discuss in detail about DOS and WINDOWS in the next module.

So without system software it is impossible to operate your computer.

In-text questions 1

1. What are program, programming and software?

2. Differentiate between system software and application software.

3. Write True or False

The set of instructions given to the computer is called programming.
Application Software is a set of programs to carry out operations for a specific application.
UNIX is a multi-user operating system.

What is language?

You are aware with the term language. It is a system of communication between you and me. Some of the basic natural languages that we are familiar with are English, Hindi, Oriya etc. These are the languages used to communicate among various categories of persons. But how you will communicate with your computer. Your computer will not understand any of these natural languages for transfer of data and instruction. So there are programming languages specially developed so that you could pass your data and instructions to the computer to do specific job. You must have heard names like FORTRAN, BASIC, COBOL etc. These are programming languages. So instructions or programs are written in a particular language based on the type of job. As an example, for scientific application FORTRAN and C languages are used. On the other hand COBOL is used for business applications.

Programming languages

There are two major types of programming languages. These are Low Level Languages and High Level Languages. Low Level languages are further divided in to Machine language and Assembly language.

Low Level Languages

The term low level means closeness to the way in which the machine has been built. Low level languages are machine oriented and require extensive knowledge of computer hardware and its configuration.

Machine Language

Machine Language is the only language that is directly understood by the computer. It does not needs any translator program. We also call it machine code and it is written as strings of 1’s (one) and 0’s (zero). When this sequence of codes is fed to the computer, it recognizes the codes and converts it in to electrical signals needed to run it. For example, a program instruction may look like this: 1011000111101

It is not an easy language for you to learn because of its difficult to understand. It is efficient for the computer but very inefficient for programmers. It is considered to the first generation language. It is also difficult to debug the program written in this language.

Advantage

The only advantage is that program of machine language run very fast because no translation program is required for the CPU.

Disadvantages

It is very difficult to program in machine language. The programmer has to know details of hardware to write program.
The programmer has to remember a lot of codes to write a program which results in program errors.
It is difficult to debug the program.

Assembly Language

It is the first step to improve the programming structure. You should know that computer can handle numbers and letter. Therefore some combination of letters can be used to substitute for number of machine codes.

The set of symbols and letters forms the Assembly Language and a translator program is required to translate the Assembly Language to machine language. This translator program is called `Assembler‘. It is considered to be a second-generation language.

Advantages:

The symbolic programming of Assembly Language is easier to understand and saves a lot of time and effort of the programmer.
It is easier to correct errors and modify program instructions.
Assembly Language has the same efficiency of execution as the machine level language. Because this is one-to-one translator between assembly language program and its corresponding machine language program.

Disadvantages:

One of the major disadvantages is that assembly language is machine dependent. A program written for one computer might not run in other computers with different hardware configuration.

In-text questions 2

1. What is the difference between FORTRAN and COBOL?

2. Differentiate between machine language and Assembly language.

3. Write True or False

Low level language and High level language are two major types of programming languages.
Machine language is the only language that is indirectly understood by the computer.
Assembly language is second generation language.

High level language

You know that assembly language and machine level language require deep knowledge of computer hardware where as in higher language you have to know only the instructions in English words and logic of the problem irrespective of the type of computer you are using.

Higher level languages are simple languages that use English and mathematical symbols like +, -, %, / etc. for its program construction.

You should know that any higher level language has to be converted to machine language for the computer to understand.

Higher level languages are problem-oriented languages because the instructions are suitable for solving a particular problem. For example COBOL (Common Business Oriented Language) is mostly suitable for business oriented language where there is very little processing and huge output. There are mathematical oriented languages like FORTRAN (Formula Translation) and BASIC (Beginners All-purpose Symbolic Instruction Code) where very large processing is required.

Thus a problem oriented language designed in such a way that its instruction may be written more like the language of the problem. For example, businessmen use business term and scientists use scientific terms in their respective languages.

Advantages of High level languages

Higher level languages have a major advantage over machine and assembly languages that higher level languages are easy to learn and use. It is because that they are similar to the languages used by us in our day to day life.

Compiler

It is a program translator that translates the instruction of a higher level language to machine language. It is called compiler because it compiles machine language instructions for every program instructions of higher level language. Thus compiler is a program translator like assembler but more sophisticated. It scans the entire program first and then translates it into machine code.

The programs written by the programmer in higher level language is called source program. After this program is converted to machine languages by the compiler it is called object program.

Higher level language

———————————- ® (Compile) ® Program Machine Language Program

A compiler can translate only those source programs, which have been written, in that language for which the compiler is meant for. For example FORTRAN compiler will not compile source code written in COBOL language.

Object program generated by compiler is machine dependent. It means programs compiled for one type of machine will not run in another type. Therefore every type of machine must have its personal compiler for a particular language. Machine independence is achieved by using one higher level language in different machines.

Interpreter

An interpreter is another type of program translator used for translating higher level language into machine language. It takes one statement of higher level languages, translate it into machine language and immediately execute it. Translation and execution are carried out for each statement. It differs from compiler, which translate the entire source program into machine code and does involve in its execution.

The advantage of interpreter compared to compiler is its fast response to changes in source program. It eliminates the need for a separate compilation after changes to each program. Interpreters are easy to write and do not require large memory in computer. The disadvantage of interpreter is that it is time consuming method because each time a statement in a program is executed then it is first translated. Thus compiled machine language program runs much faster than an interpreted program.

In-text question 3

1. What is the difference between interpreter and compiler

2. Give some examples of high level language.

3. Write True or False

High level languages are problem-oriented language.
Object program generated by compiler is machine independent.
The disadvantage of interpreter is that it is time consuming.

What you have learnt

In this lesson we discussed about two types of software, namely, system software and application software. System software controls the hardware part of the computer. It is designed for performing tasks such as controlling all operations required to move data into and out of the computer. It communicates with printer, card reader, disk, tapes, etc. and monitors the use of various components like memory, CPU, etc. DOS, Unix and Windows are three important system software. Application software is a set of programs written for specific purpose. Examples of application software are Microsoft Word, Lotus 1-2-3, COBOL, BASIC and FORTRAN. We have discussed about levels of computer language.

Terminal questions

What is software and hardware?
What is computer Language?
Name the three different categories of computer languages.
What is machine language? Why is it required?
What are advantages and disadvantages of machine language?
What is assembly language? What are its advantages over machine languages?
What is the difference between source program and object program?
What is higher level languages? Why are higher level languages are easier to use.
What is compiler? Why is it required?
What is interpreter? How does it differ from compiler?

Feedback to in-text questions

In-text questions 1

1. Program is a set of instructions given to the computer by the user. Software is a set of computer programs and procedures that describe the programs. Programming is the process of software development.

2. Application Software is a set of programs to carry out operations for a specific application. System software is a set of programs written for performing tasks such as controlling all operations required to move data into and out of the computer.

3. 1. False 2. True 3. True

In-text questions 2

1. FORTRAN is used for scientific applications whereas COBOL is used for business applications.

2. Machine Languages are the only language that is directly understood by the computer. It is written in binary form that is 0 and 1. The set of symbols and letters forms the Assembly Language.

3. 1. True 2. False 3. True

In-text questions 3

1. Both compiler and interpreter are program translators used for translating higher level language into machine language. While compiler scans the entire program first and then translates it into machine code, an Interpreter translates the program line by line.

2. FORTRAN (Formula Translation) and BASIC (Beginners All-purpose Symbolic Instruction Code) are some of the high level languages.

3. 1. True 2. False 3. True

Operating system

Computer 11 Notes — Sun, 08 Apr 2012 05:41:42 +0000

Operating system is an interface between computer and hardware and application software. Without OS no computer can be operated. Operating system is regarded as the heart of living being for a computer system.
In other words, OS is defined as a program or suit (support for) of programs that controls the entire operation of the computer, such as recognizing input from keyboard, sending output to the display screen keeping track of files and directories on the disk and controlling peripheral devices such as disk drives and printers.

Basic organization of operating system:

Email Service

Computer 11 Notes — Sun, 08 Apr 2012 05:41:42 +0000

Email service is used for transmitting electronic or soft-copy documents, message by using electronic devices like computer, computer network, internet, etc. present e-mail service is based on stored and forward concept i.e. email sent by the sender is stored in email server before forwarding it to the receiver. It doesn’t require the sender and receiver to be connected at the same time. Traditionally, the older concept of email required both sender and receiver to be connected at the same time.
It uses protocols like SMTP, POP, IMAP, etc.

Features of e-mail:

It is faster and cheaper medium of communication.
It is reliable.
It is secured communication.
It can be used for transmitting text, image, audio, video.
Same message can be sent to multiple users at the same time by using CC (Carbon Copy) and BCC (Blind Carbon Copy).
It may or may not use internet directly.

Types:

Web based email
POP email service

1. Web based email:
It is the internet based mailing system. It requires internet connection and a browser to send or receive the message. Email providers like hotmail.com, yahoo.com, gmail.com, etc. provide internet based email. It is the most widely used email service.

2. POP email service:
This email service is provided by local email or network providers. It requires connection to the e-mail provider and email client software like:

Outlook express
Thunderbird
Eudora
Kmail, etc.

It can be used from the system with email client software and proper setting to connect email providers.

Model Question For Computer Science Class 11

Computer 11 Notes — Sun, 08 Apr 2012 05:41:42 +0000

HSEB question model of computer science

Grade : 11

For : 2070

Time : 3hrs
F.M. : 75
P.M : 27

Group A (long answer question)

Attempt all the questions. [3 X 10 = 30]

1. Draw a well-labeled diagram of typical architecture of a computer system and explain the main function of Control Unit and ALU. [4+3+3]

2.
1. What is an operating system ? Explain any three function of an operating system.
2. The “WiMP” environment is much more user-friendly, why ?
OR
1. What is cell addressing and explain different types of cell addressing used in spreadsheet.
2. Write a tag to design your personal web page to link photo family, background and banner page using frame. [5+5]

Define flowchart and pseudocode. Explain their significance in programming. [5]
Write a pseudocode to accept any three numbers and output the largest among them. [5]

Group B (Short answer questions)

Attempt any **nine questions. [9 X 5 = 45]**

4. Classify the computers according to their generation based on the technology used. [5]

5. Differentiate between analogue and digital computer, explain with examples. [5]

6. What do you mean by number system? Why do digital computers use binary numbers for their operation ? [2 + 3]

7. Convert these numbers. [5]

1. (126)10 = (?)2
2. (11011)2 = (?)10
3. (57)8 = (?)2

Perform following operations.

4. 1011 – 1001
5. 1110 + 1110

8. State the Demorgan’s theorem and verify it. [5].

9. What are logic gates? Construct the truth table of NOR operation. [5]

10. Write short notes on (any two) : [5]

IDE 2. SCSI 3. Wave Camera

11. What are uses of internet ? Write any five search engine name. [5]

12. Differentiate between System Software and Application Software with examples. [5]

13. What are DPT features in MS-Words? Write three features of Presentation Packages. [2 + 3]

14. Write an algorithm and flowchart to print the word “Hello” ten times using “while loop” [5]

Interrupt

Computer 11 Notes — Sun, 08 Apr 2012 05:41:42 +0000

It is the events that makes the processor stop executing its program to perform some requested activity. There are two types of interrupts they are:

1. Hardware interrupt:
Interrupts generated by hardware devices such as keyboard, mouse, printer or chips on the system board is called hardware interrupt. Some examples of hardware interrupt are video card wants memory access, USB scanner has data, mouse moves, key pressed on keyboard, etc.

2. Software interrupt: Interrupts signals generated or caused by the programs or software are called software interrupts. Some examples: interrupt generated by the ROM BIOS during the start up for the computer, virus threat notification by the antivirus software, etc.