CONVERSIONS FROM BINARY TO HEXDECIMAL NUMBERING SYSTEMS

6-18-13
Computer strategies and logic
Intro to computers

The abacus wasn’t electronic but was the first computing device
Charles Babbage Mechanical computer developed in 1822 and 1871 w/thousands of moving parts.

The Hollerith machine was the first electronically driven machine in the late 1800s
Hollerith left the Census bureau in 1896 to establish the Tabulation Machine. Later became IBM

The first digital computer built in the basement of Iowa state university in 1937-1942 by John atanasoff First electronic digital computer First with Binary math, Parallel processing regenerative memory, and separate memory

First digital cpu
Weight 750 pounds
Stored 3k bits
Company later called Atasasoff- Berry Company (ABC)
2 forms of electronics
Digital is 2 volts 0 (0) and 5 (1)
Analog computer is an infinite number of voltages (NO BINARY)

WWII
Tommy flowers (British) made the code breaking computer called colossus to break German messages in 1943

John Von Nuemann
1945
Computers are reprogrammed without need for rewiring aka “stored program technique”

ENIAC (Electronic numerical integrator and computer)
1946 John Mauchly, John Eckert
Thirty tons
19k vacuum tubes
1500 relays
200 KW of power considered the prototype of today’s computers
This had the original patent for electronic computer later given to Atanasoff

Von Nuemann Computer model
1940s model
Two main units CPU and storage structure (Memory RAM)
RAM- Random Access Memory
Basis of most computers used today
RAM bit, byte, binary, ASCII
Bit- binary digit (0,1)
Byte- group of 8 bits
Binary- system of 0’s and 1’s American standard for code for information
Control unit- reads and interprets instructions
ALU math and logic (AND, OR, and NOT)

Biggest change to model, Cu and ALU became computer chip
Cache- internal memory in processor, very quick
All processors have some level of cache

Von Nuemann model
5 parts
Cpu- brain
Working storage RAM
Permanent storage – ROM, hd, optical disks, etc.
Input devices- mouse, keyboard
Output devices- Monitors, printers

Xerox
1970
Founded Palo Alto Research Center (PARC)
Created many technologies such as graphics mouse GUI ETHERNET and more, to be later taken by apple and microsort

Four generations
1st vacuum tubes
2nd transistors
3rd Integrated Circuits
4th Microprocessors

From tubes to transistors
Modern digital computer is a collection of electronic switches. control routing data aka binary digits
Tubes were inefficient and unreliable. Consist of cathode plate and control grid
In 1947 the transistor was developed by Bell Labs (Bardeen, Brattain, and Shockley)
Two main transistors- BJT AND MOSFET
2 jobs switch and amplify
The MOSFET is the transistor is the most common.
( Metal Oxide Semiconductor Field Effect Transistor)
Easily damaged by static electricity therefore its always better to handle motherboards RAM and CPUs by edges or use ESD
ESD- electrostatic discharge with Mats, Wrist Straps
If no ESD, touch the power supply often
MOSFET is a lower power than the BJT

History of PCs
January 1975 MITS (Micro Instrument and Telemetry Systems) developed the Alkair kit which prompted the software companies to write programs CP/M (OS) and Windows BASIC
Altair was first PC in 1975 for 395$ in kit form (Still needed to be built and soldered
IBM saw that standardization was the future and started sharing their information with other companies (Wise move)
Used Intel Processors, Microsoft OS, and developed physical standardization
Moore’s Law- Gordon Moore (Intel’s cofounder) stated that performance and capacity doubles over every 1.5 to 2 years
AMD and Intel, competitors for microprocessors or Cpus
Intel Microsoft and AMD are primarily responsible for advances in software and hardware for PCs
2006 apple began to use Intel Microprocessors

What is a PC
Personal Computer
PCs are IBM compatible
Who controls software standard
Microsoft (Operating systems control the computer) and hardware standards?
Intel (Microprocessors run the hardware)