Understanding Spreadsheets: Concepts, Formulas, and Functions
Understanding Spreadsheets
Spreadsheets originated with the idea of creating programs to perform simple calculations (1974). The first program to load a worksheet was VisiCalc, which allowed for grid calculations.
Initial Concepts
- Worksheet: A grid that allows calculations with rows and columns.
- Row: A horizontal series of cells.
- Cell: An individual box in the worksheet used to enter numeric, alphabetic, or formula-based data.
- Reference: The name of a cell, used to refer to its contents in formulas.
- Workbook:
Computer Architecture and Organization Glossary
MAR (Memory Address Register): A CPU register used to hold the address of the memory location being accessed.
1’s Complement Representation: Used in representing binary numbers by complementing each 1 to 0 and each 0 to 1.
2’s Complement Representation: Used in representing binary numbers. Positive values are in sign-magnitude. Negative values are represented by adding 1 to the 1’s complement of the number.
Absolute Address: An address that identifies a memory location without using intermediate references.
Read MoreNumber Systems, Pointers, Arrays, and MIPS Registers
Number Systems
Data types:
int: 4 bytesfloat: 4 bytesdouble: 8 byteschar: 1 byte
Format Specifiers:
%d: int%f: float%p: pointer%c: char
Converting Base-R to Decimal
Example: 1101.102 = 1 * 23 + 1 * 22 + 0 * 21 + 1 * 20 + 1 * 2-1 + 0 * 2-2
Converting Decimal to Base-R
For Whole numbers: Repeated division by R until the quotient is 0. The remainders form the answer, with the first remainder being the least significant bit (LSB).
For Fractions: Repeated multiplication by R until the fractional part is 0. The
Read MoreSoftware Design Concepts: Analysis, Models, and Architecture
1). Concept Analysis
The analysis concept is basically to understand the business rules and software requirements in order to provide an optimal solution to the problem, with clear aims and objectives. It also defines the scope of the project and the functional and non-functional requirements. It consists of several stages:
- Recognize the problem: which recognizes the basic elements of the problem as perceived by end users.
- Evaluation and synthesis, which assesses the information content, defines and
Computer Ethics: Security, Privacy, and Best Practices
Computer Ethics
Moral guidelines that govern the use of computers and information systems. For example, it involves the unauthorized use of computers and networks, software theft, information accuracy, codes of conduct, and information privacy.
Encryption and 3 Encryption Methods
Encryption safeguards against information theft. It is the process of converting plaintext (readable data) into ciphertext (unreadable characters) through an encryption key (the formula) that often uses more than one method.
Read MoreOperating System Fundamentals: Processes, Memory, and Security
Operating Systems: Core Concepts and Mechanisms
Process Scheduling
Round-robin scheduling is a preemptive algorithm that distributes CPU time equally among tasks in an operating system. However, it doesn’t take priority into account. Another issue is that a process might not have any work to do, so it must be actively skipped.
Daemons
Daemons open automatically and run in the background without the user’s input or control. They often start when the computer boots.
What is an Operating System?
There isn’
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