Hardware ( Not so hard really )
Introduction to Computers What is a computer? Why use a computer anyway? Do they have limitations? What s next?
A bit of history Mechanical Early 1614 1643 1673 Abacus Slide Rule (John Napier) Adding and Subtracting machine (Pascal) Multiplying Machine (von Leibnitz)
A bit more History Sophisticated Mechanical 1820 Difference Engine (Babbage) Designed to calculate polynomials of the form x2+3x+20 to 6 decimal places 1840 Analytical Engine (Babbage) Machine to calculate any arithmetic operation. Important idea was that it could store the series of operations to be made (elementary program). Unable to be built because technology required was too advanced.
Even more history Electronic 1939 Electronic Computer (Atanasoff) Solved small systems of linear equations. 300 vaccuum tubes. 1946 Eniac (Eckert, Mauchly) Electronic Numerical Integrator And Computer. Stored program was used. > 18,000 vacuum tubes used.
Nearly there Transistor Based 1947 1959 Second Generation The invention of the transistor replaced the vacuum tubes but were much smaller and required less power. Third Generation The transistor was replaced by the integrated circuit. Reduction in size, increase in speed, and reduction of power. 1975+ Fourth Generation Large Scale Integration. Whole microprocessors on a single chip.
Modern times Powerful CPUs Multiple CPUs Networking Clusters
Towards 3000 Where are computers heading? Where is the technology heading? What is being done at Griffith?
A first look at a computer Computers do not think. Data Computer Information The computer needs the data in a form that it can understand.
Data representation The processing in the computer and the processing instructions with the data is stored in the memory. The memory is made up of millions of tiny transistor circuits. The transistor circuits act as tiny switches. The switches can be either ON or OFF. ON is 5V and is represented by a 1. aside: 3.3V, 1.2V as well OFF is 0V and is represented by a 0.
A bit of information This is a binary (base 2) system. Each 1 or 0 is called a bit (binary digit) Therefore the computers requires its world to be represented as binary. All inputs, outputs, and processing instructions must be represented as binary in the computer.
Binary Base 2 Written as a b following the word eg 10b. Counts from 0 to 1 before requiring another column. Each column is significant since it 2 times the previous column. 1b = 1 decimal 10b = 2 decimal 100b = 4 decimal
It counts Dec 0 1 2 3 4 5 6 7 8 Binary 0 1 10 11 100 101 110 111 1000
It counts Dependant upon powers of 2. 2 0 = 1b = 1 2 1 = 10b = 2 2 2 = 100b = 4 2 n = 1 with n zeros in binary.
A bit of humour (perhaps) There are 10 types of people that understand binary : Those that do And Those that don t
Binary to decimal 101b= (1 x 2 2 ) + (0 x 2 1 ) + (1 x 2 0 ) = (4) + (0) + (1) = 5 (decimal)
Decimal to Binary divide the decimal by 2 until the result is 0. the remainder from each division gives the binary result. the binary number is built from the right.
Example 53 = 1 1 0 1 0 1 b division result remainder 53 / 2 26 1 RHS 26 / 2 13 0 13 / 2 6 1 6 / 2 3 0 3 / 2 1 1 1 / 2 0 1 LHS
Hexadecimal Large binary numbers can be too unwieldy for humans to use. It is easier to group the binary numbers into the more manageable size of 4 bits. Hexadecimal is base 16. i.e. 24 = 16h. Written as an h following the number or a 0x preceding the number eg 23h or 0x23. Counts from 0 to F before requiring another column. Each column is significant since it 16 times the previous column.
Hex counts too! Decimal 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Hexadecimal 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F 10
The power of the hex Dependant upon powers of 16. 16 0 = 1h = 1 16 1 = 10h = 16 16 2 = 100h = 256 16 3 = 1000h = 4096 16 n = 1 with n zeros in hexadecimal.
Binary / Hex conversions Binary to hex 1010 1111 0010 0011 b A F 2 3 h Hex to binary A F 2 3 h 1010 1111 0010 0011 b
Dec / hex conversions Hex to dec FA2h = (F x 16 2 ) + (A x 16 1 ) + (2 x 16 0 ) = (15 x 256) + (10 x 16) + (2 x 1) = (3840) + (160) + (2) = 4002 Hex to dec
Dec / hex conversions cont Hex to dec find the highest power of 16 that divides the decimal number to give a number less than 16. divide the remainder by the next lowest power of 16 etc the result of each division gives the hexadecimal digit. 12 = 12 * 1 = Ch 18 = 1*16 + 2*1 = 12h 128 = 8*16 + 0*1 = 80h 253 = 15*16 + 13*1 = FDh
ASCII Codes (ANSI X3.4) DEL ~ } { z y x w v u t s r q p 7 o n m l k j i h 9 f e d c b a ' 6 - ^ ] \ [ Z Y X W V U T S R Q P 5 O N M L K J I H G F E D C B A @ 4? > = < ; : 9 8 7 6 5 4 3 2 1 0 3 /. -, + * ) ( ' & % $ # ''! space 2 US RS GS FS ESC SUB EM CAN ETB SYN NAK DC4 DC3 DC2 DC1 DEL 1 Sl SO CR FF VT LF HT BS BEL ACK ENQ EOT ETX STX SOH NUL 0 F E D C B A 9 8 7 6 5 4 3 2 1 0 *
Extended ASCII Codes
Conceptual Computer Application Software Operating System Hardware
Hardware: Model
Memory - Ram Data in (write) Clock (synchronous) FF www.pctechguide.com Data out (read) A single flip-flop does not hold enough information. Therefore memory is a large collection of flip-flops. eg. 8 x 8388608 bits = 8 Meg. Memory arranged into more manageable sizes. Bytes or words Data In Data Out Clock
Memory Sizes A BYTE is a collection of 8 bits. A WORD is machine dependant and is usually 16 or 32 or 64 bits. 1K is 1,024 bytes. 1M is 1024K bytes 1G is 1024M bytes
Read Memory Address Bus Data Bus Read / Write Lines Memory Address passed to memory on the address lines (BUS). A read command is issued. Memory puts the contents of the byte on the data bus.
Write Memory Address Bus Memory Address passed to memory on the address lines (BUS). Data Bus Read / Write Lines A write command is issued. The data on the data bus is written to the memory.
CPU Irv Englander, The Architecture of Computer Hardware and Systems Software www.pctechguide.com
Program Execution ADDRESS INSTRUCTION DATA 2000 BB 00 01 1. Fetch instruction 2003 8A 07 2. Decode 2005 43 3. Fetch data if required 2006 2008 200A 8B FB 43 07 08 4. Execute 5. Point to next instruction 200B 88 07
Storage Disk Type Platters Heads Cylinders Sectors Block Size (bytes) Speed (rpm) Seek Time (msec) Latency (msec) Transfer Rate (bytes/sec) 3.5 floppy 1 2 80 18 512 360 95 83 54K 100MB Zip 1 1 360 56 512 2941 29 10 1.4M 4.3GB HDD 8 15 8912 63 512 5400 10.5 5.5 2.8M 20.4GB HDD 3 6 13328 250 1K 7200 8.5 4.2 66M DVD 1 1 spiral var 2352 var 250 var 2.5MB Irv Englander, The Architecture of Computer Hardware and Systems Software
Storage: HDD www.pctechguide.com
Storage: HDD www.pctechguide.com
Storage: CD Irv Englander, The Architecture of Computer Hardware and Systems Software CDR www.pctechguide.com CDRW
Storage: CD CD HDD Irv Englander, The Architecture of Computer Hardware and Systems Software
Storage: DVD www.pctechguide.com
Storage: Raid Level 0: Data Striping at block level Level 1: Disk Mirroring Level 3: Same as level 0 but uses parity disk www.pctechguide.com Level 5: Data striping and parity at byte level
Input: Keyboard A 0100 0001 To computer www.pctechguide.com
Input: Mouse www.pctechguide.com
Output: Monitor www.karbosguide.com
Output: CRT Phosphor Dot Electron Gun X & Y Deflection Plates Screen
Output: LCD www.pctechguide.com
Computer System Irv Englander, The Architecture of Computer Hardware and Systems Software
Computer System: Motherboard www.build-a-computer-guide.com
Real Computer System