COMPUTER MERIT BADGE - Jeremy Hubble, 8/15/89
Programs:
A program is a set of instructions for the computer to follow. They are created by first using an editor to write the SOURCE CODE, which is usually an ASCII text file which contains English instructions. Then the source code is run through a compiler, which checks for errors, and compiles the source into machine language OBJECT CODE. (The object code is the actual program that can be executed.) Before the final edition of a program can be actually released, it usually has to be DEBUGGED, and modified many times. Debugging is the processes of remove all BUGS (mistakes, typos, and other problems in the program.) In an interpreted language, such as BASIC the program is interpreted into machine language as it is being run, instead of before it is run.
History:
The first totally electronic computer, ENIAC (electronic numerical integrator and computer) was created in 1946 at the University of Pennsylvania, and could do several hundred multiplications per second. (Today most home computers average from 300,000 to 2,000,000 instructions per SECOND.) ENIAC took up an entire room, and had to be rewired each time a new program was formed, and contained 18,000 vacuum tubes. Later, with the advent of the transistor, the vacuum tubes were replaced with transistors, and the size of computers greatly reduced. In the late 1960s, the integrated circuit was introduced, allowing many transistors, and their connecting wires to be placed on a silicon chip. In the mid-1970's the microprocessor became available, signifying the start of the home computer era. Some of the first computers available to the general public were the PET, and the APPLE, both using the 6502 microprocessor. At about the same time, the CP/M standard, using the Z80 microprocessor started to take form in the business community. In 1982, Commodore introduced its Commodore 64, which quickly became one of the most popular computers of all time, and found its way into over 6 million households. The quick success of the computer industry in the early 1980s brought on a flood of software developers, but after sells started to level off, many of the companies went bankrupt. In 1981, IBM introduced its PC. After a few years, the power of the PC began to expand, and a surge of clonemakers appeared, marketing IBM compatible computers, which soon reached many American businesses and homes.
BASIC (Beginner's All-Purpose Symbolic Instruction Code)
- Included with most home computers. Used mainly as a first programming language. Because it is an interpreted language, it is not usually used for professional programming purposes. (Compilers do exist, but they usually produce code that is slower, and larger than code of other languages.)
C
- A simple language which is greatly expandable, by use of additional functions. Can be used as either a structured or unstructured programming language. Easily portable to other computers. Popular programming language for most commercial software products available today, including games, spreadsheets, communications programs, and many other applications.
Assembly Language (Machine Language)
- The computer's native language. Anything that can be written in another language can be written in Assembly language. Uses a series of bytes representing different instructions for the program to carry out. It is the most efficient programming language available today, but, it varies greatly from computer to computer, and takes much longer to program in. Assembly Language is mainly used in areas of programs where greater speeds are desired. Also commonly used for games, and utilities.
Uses of Computers:
Programming - games, applications, utilities, school
Telecommunicating - talking to other people, download programs
Word Processing - writing letters, talks, reports, etc.
Spreadsheeting - family budget, collection
Databasing - indexing tapes, stamps, coins, etc.
Jobs in Computer Field
| Programming | Software distribution | Manufacturing |
| Writing | Service and Repair | Engineering |
| Consulting | Sales | Word Processing |
Input/Output Devices
Disk drive - 5.25, 3.5 (micro), density-(1,2,high), sides - single, double
Printer - Line Feed, form feed, CPS, NLQ, LQ, Daisy wheel, tractor/friction feed
Hard Drive - fixed disk, partitions, megabytes
Modem - baud, bps, data compression, error correction, auto dial/answer
Monitor - CRT, RGB, monochrome, VGA, EGA, TV, color
Storage Media
Disks - (see disk drive), flippies, write protected
Cassette Tapes, Tape Backup; CDs; Harddrive (see above); cartridges
Computer Hardware
(see I/O devices); CPU - mhz, MIPS, 286, 6502, 68000, microprocessor
Peripherals; keyboard, joysticks, mouses, trackballs, cartridges
Computer Software
(see storage media) - shareware, freeware, public domain, commercial
games, applications, utilities, communications
Flowcharts
- start/stop; - I/O; - choice; - operation
10 input A:input B:C=A+B:print A;"+";B;"=";C
start -> get a -> get b -> C=A+B -> print result
digital computers - computer, calculator, digital watch, nearly everything
analog computer - abacus, other manual stuff like that