Day 1 Definitions:
1. Hardware – The physical equipment. Hard drives, CPU, console, tapes, printers, etc.
2. Software – programs.
3. Programs – set of instructions.
4. Instruction – a command to the computer to do something.
COBOL
Add sales to tot-sales
Basic
ts = s + ts
Fortran
ts = s + ts
Pascal
ts:= s + ts
Assembly
ap ts, s
DOS
dir
5. Machine Language
101111101110100000101000
6. Source Code
- Code programmers write
7. Assembly Language – first and only low level language.
8. Assembler program
9. Low level language – each instruction you write is converted to a machine level instruction. 1 – 1
10. High level language – each instruction you write is converted to 1 or more instructions.
11. Fortran – first high level language.
12. COBOL
CPU
13. C++
Control Unit
14. CPU – Central Processing Unit
- - - - - - - - - - = control
Input
Memory
Output
____________ = instructions
=========== = data
ALU
15. Control Unit – the brain – executes instructions.
16. Memory – Core Storage – Ram -- stores data and instructions.
17. Arithmetic Logic Unit – arithmetic and logic operations are done here.
17a. Data and instructions go from Input to Memory.
Instructions go up to the Control Unit and are Executed.
Data goes down to the ALU, back up to Memory, and out to the Output device.
18. Bits
19. Bytes – a consecutive group of bits that has some meaning.
20. Fields – a consecutive group of bytes that has some meaning.
a. Well defined fields.
b. Not well defined fields
21. Records - a consecutive group of fields that has some meaning.
22. File - a consecutive group of records that has some meaning.
- anything you save on a disk.