174 Software
HAdm Business Computing
Lecture Roadmap
Using Computers/Security Digital Representation of Information Database Hardware Software Networks Internet / Web
What's important?
The abbreviated family tree
Jacquard Babbage 1820
1804
Computer Concepts Illustrated. Accessed: 2-16-00. www.ualr.edu/~gblane/cpsc1370/presentations/History/History_files/v3_document.htm
The Stored Program Concept
John von Neumann (1903--1957)
Software in Program Files
Files Data Program System Application
What do we need software for?
Hardware
Software: OS
Hardware
Operating System
Operating System
Operating System
The OS "Big Picture"
It manages the hardware and software resources of the system, such as the processor, memory, disk space, etc. It provides a stable, consistent way for applications to deal with the hardware without having to know all the details of the hardware.
Howstuffworks.com
Different types of OS
Single-user, single task Single-user, multi-tasking
Real-Time
Multi-user
The Power-up Sequence
1024 KB
Push the power button Software in ROM is in control Power on self-test (POST) Read/Write to all memory addresses
The Power-up Sequence
Phoenix BIOS v3.45 2001-2005 F2 to enter setup
BIOS is loaded Opportunity to enter setup (e.g. F2)
The Power-up Sequence
_
BIOS searches drive order for OS Drive activity lights will flash
The Power-up Sequence
When OS is found, it is loaded
Starting Windows
The Power-up Sequence
Once critical OS code is in RAM, control is transferred to the OS for the remainder of the startup Drivers, libraries, etc, loaded
The Power-up Sequence
User interface loaded and rendered Additional processes started, such as virus protection (watch your system tray)
OS Specific Responsibilities
Processor management Memory management Device management Storage management Application interface User interface
Processor Management
A process occupies a certain amount of RAM. It also makes use of registers, stacks and queues within the CPU and operating-system memory space. When two processes are multi-tasking, the operating system allots a certain number of CPU execution cycles to one program. After that number of cycles, the operating system makes copies of all the registers, stacks and queues used by the processes, and notes the point at which the process paused in its execution. It then loads all the registers, stacks and queues used by the second process and allows it a certain number of CPU cycles. When those are complete, it makes copies of all the registers, stacks and queues used by the second program, and loads the first program.
Howstuffworks.com
Primary Storage (RAM)
Control Unit Registers Arithmetic/Logic Unit R0 5 5 R1 3 A R2 1 B R3 Instruction Register 3 0 B 2 Bus Program Counter A 6
Program Data
A0 1 1
A1 B 0
B0 3 A
B1 1 B B2
A2 1 2
A3 B 1 A4 5 0
B3
B4
A5 1 2
A6 3 0
B5
B6
A7 B 2
RF A8 C 0 A9 0 0
B7
B8 B9
FETCH EXECUTE
DECODE
Secondary Storage
Primary Storage (RAM)
Control Unit Registers Arithmetic/Logic Unit R0 5 5 R1 3 A R2 1 B R3 Instruction Register 3 0 B 2 Bus Program Counter A 6
Program Data
A0 1 1
A1 B 0
B0 3 A
B1 1 B B2
A2 1 2
A3 B 1 A4 5 0
B3
B4
A5 1 2
A6 3 0
B5
B6
A7 B 2
RF A8 C 0 A9 0 0
B7
B8 B9
FETCH EXECUTE
DECODE
Secondary Storage
Primary Storage (RAM)
Control Unit Registers Arithmetic/Logic Unit R0 F F R1 C 7 R2 R3 Instruction Register 1 2 D 2 Bus Program Counter C 1
Program Data
A0 1 1
A1 B 0
B0 3 A
B1 1 B B2
A2 1 2
A3 B 1 A4 5 0
B3
B4
A5 1 2
A6 3 0
B5
B6
A7 B 2
RF A8 C 0 A9 0 0
B7
B8 B9
FETCH EXECUTE
DECODE
Secondary Storage
Processor Management
A process occupies a certain amount of RAM. It also makes use of registers, stacks and queues within the CPU and operating-system memory space. When two processes are multi-tasking, the operating system allots a certain number of CPU execution cycles to one program. After that number of cycles, the operating system makes copies of all the registers, stacks and queues used by the processes, and notes the point at which the process paused in its execution. It then loads all the registers, stacks and queues used by the second process and allows it a certain number of CPU cycles. When those are complete, it makes copies of all the registers, stacks and queues used by the second program, and loads the first program.
Howstuffworks.com
Processor Management
RAM
Process PCB Process PCB Process PCB
.
CPU
Processor Management
RAM
Process Process PCB Process PCB
. PCB CPU
Processor Management
RAM
Process PCB Process PCB
Process . PCB CPU
Processor Management
RAM
Process PCB Process PCB Process PCB
.
CPU
Processor Management
RAM
Process PCB Process Process PCB
. PCB CPU
Processor Management
RAM
Process PCB Process PCB
Process . PCB CPU
Processor Management
RAM
Process PCB Process PCB Process PCB
.
CPU
Processor Management
RAM
Process PCB Process PCB Process
. PCB CPU
Processor Management
RAM
Process PCB Process PCB
Process . PCB CPU
Processor Management
RAM
Process PCB Process PCB Process PCB
.
CPU
Memory & Storage Management
Each process must have enough memory in which to execute, and it can neither run into the memory space of another process nor be run into by another process. The different types of memory in the system must be used properly so that each process can run most effectively.
Howstuffworks.com
Memory Management
CPU
Cache
RAM
Virtual Memory
Disk Storage
Small/Fast/Expensive/Volatile
Big/Slow/Cheap/Permanent
Real vs. Virtual RAM vs. Disk Space
Windows XP Professional alone is about 1.5GB, but my computer has only 1GB of primary memory... I have a problem!
If Valerie is virtual, then what exactly does virtual mean?
We use the term virtual to refer to a characteristic whose existence is simulated with software rather than actually existing within hardware.
Virtual Valerie
Virtual Memory
Primary Storage
Program A Pg 1
Secondary Storage
Primary Storage
Program Pg A 5
Program A Pg 3
Program A Pg 7
Program A Pg 2
Program A Pg 14
Virtual Memory Pages
time "t"
time "t+1"
Virtual Memory
Device Management
Inkjet printer
Driver
My Document
Operating System
Driver
Driver
Laser printer
Just print it!
Fax
Application Interface
Provides to application programs a consistent, predictable means to access information from the operating system, as well as to direct its activities.
Application Interface Example
theFile = Application.GetOpenFilename() An application uses the API to find out which file a user wishes to open.
The OS responds by giving the user a standard, recognizable means to select a file.
C:\174 Lecture 9-10\Hardware.ppt
The OS informs the application the exact name and location of the file the user wants to open.
User Interface
Just as the API provides a consistent way for applications to use the resources of the computer system, a user interface (UI) brings structure to the interaction between a user and the computer.
System Software
Hardware Operating System System Software
System Software
System Software
Application Software
Applications
Software Suites
Hardware
Operating System System Software
Application Software
Application Software
The User Interface Gap
Command Line
Translation by the User
Translation by the Computer
The User Interface Gap
Menu Driven Command Line
Translation by the User
Translation by the Computer
The User Interface Gap
GUI
Menu Driven Command Line
Translation by the User
Translation by the Computer
The User Interface Gap
Voice Recognition
GUI
Menu Driven Command Line
Translation by the User
Translation by the Computer
The User Interface Gap
Natural Language Voice Recognition
GUI Menu Driven Command Line
Translation by the User
Translation by the Computer
We build our computers the way we build our cities over time, without a plan, on top of ruins.
--Ellen Ullman, Close to the Machine
Software:Interfacing problem
Machine Language
Translation by the Programmer
Translation by the Software
Machine Language
0110 0010 0110 0110 0110 0110 0010 0110 0110 0110 0110 0010 0110 0110 0110 0110 0010 0110 0110 0110 1011 1001 1011 1011 1000 1011 1001 1011 1011 1000 1011 1001 1011 1011 1000 1011 1001 1011 1011 1000 1010 1110 1010 1010 1010 1010 1110 1010 1010 1010 1010 1110 1010 1010 1010 1010 1110 1010 1010 1010 1010 1111 1110 1000 0010 1010 1111 1110 1000 0010 1010 1111 1110 1000 0010 1010 1111 1110 1000 0010
Software:Interfacing problem
Assembly Language
Machine Language
Translation by the Programmer
Translation by the Software
Assembly Language
Assembly:
Assembly Language
Assembly:
Assembler
The evolution of software
3GL
Assembly Language Machine Language
Compiling
C (3GL):
Compiler / Interpreter
Source vs. Object
0110 0010 0110 0110 0110 0110 0010 0110 0110 0110 0110 0010 0110 0110 0110 0110 0010 0110 0110 0110 1011 1001 1011 1011 1000 1011 1001 1011 1011 1000 1011 1001 1011 1011 1000 1011 1001 1011 1011 1000 1010 1110 1010 1010 1010 1010 1110 1010 1010 1010 1010 1110 1010 1010 1010 1010 1110 1010 1010 1010 1010 1111 1110 1000 0010 1010 1111 1110 1000 0010 1010 1111 1110 1000 0010 1010 1111 1110 1000 0010
Compile
Source Code
Object Code
Application Development
4GL 3GL
Assembly Language Machine Language
Fourth Generation Languages
Non procedural English like and easy Outcome driven
Slower High memory requirement "Inefficient"
SQL (4GL):
C (3GL):
Application Development
???
4GL 3GL
Assembly Language Machine Language
Computer Languages
Programming Languages
Java C# VBS JavaScript HTML XML
Scripting Languages
Mark-up Languages
Programming Language VB
Scripting Language JavaScript
Markup Language - HTML
Dividing up the work
Multithreading Multiprogramming Multiprocessing Grid computing
Multithreading
The process of "running" two or more different pieces of the same program simultaneously. Example: One part of a web browser might be listening to the Internet connection waiting for more incoming data. Another part of the browser is busy rendering a web page from data already received.
Multiprogramming
A method of executing two or more programs concurrently using the same computer. The programs are active at the same time, but they do not use the same computer resources concurrently. A group of programs take turns using the processor.
Multiprocessing
An operating system capability that links together two or more CPUs to work in parallel in a single computer system.
Grid Computing
S.E.T.I.
Search for Extraterrestrial Intelligence
Grid Computing
Open-Source
"Linux" and "Apache" Free access to source code for modifications or error fixes Not owned by any company or individual A global network of programmers and users manages and modifies the software, usually without being paid to do so
Object-Oriented Programming
A programming approach where program code and data are combined into logical classes. Classes are used to derive objects. (Classes are like cookie cutters, objects are like cookies) New classes can be created by subclassing an existing class. Objects are self-contained mini-programs, that can be swapped easily into new applications.
Classes & Inheritance
Object Invisible Object Window Scroll Bar Visible Object Control Button Menu
Command Button "Clicking" Button
Option Button
Checkbox
Java
Product of Sun Microsystems, Inc. Platform independent programming language Internet-savvy Not the same as "JavaScript" "Scares the hell out of" Bill Gates
Java
Application
OS (Windows)
Java
Application
OS (Unix)
Java
Java Application
Virtual Machine
OS (Unix)
Java
Java Application
Virtual Machine
OS (???)
Microsoft .Net
.Net Application
CLR
Windows (For Now)
Lecture Roadmap
Using Computers/Security Digital Representation of Information Database Hardware Software Networks Internet / Web