ISYS104 Lecture Notes - Thin Client, Paintshop Pro, Instruction Set
31 May 2018
School
Department
Course
Professor
Chapter 4- Hardware and Software
Computer Data
▪ Binary Digits
- Used to represent data
- Bit is either 0 or 1
▪ Sizing computer data
- Bytes
- 8-bit chunk equals 2 bytes
- Size of main memory and storage devices
How does a computer work?
▪ CPU (central processing unit)
- Transfers program or data from disk to main memory
- Moves instruction from main memory via data channel or bus
- Has small amount of fast memory called cache
o Keeps frequently used instructions
o Large cache makes computer fast, but is expensive
▪ Main memory
- Contains program instructions
- Contains operating system (OS) instructions
▪ Operating system (OS)
- Windows, Linux, Mac OS
- Progra that otrols oputers resoures
▪ Memory swapping occurs when the main memory is too small to hold all programs
and data
- CPU loads programs from memory in chunks
- Places new program into unused memory
- If none available, the operating system will remove chunk being used and replace
with requested data
- It slows down the computer processing time
Why should a manager care how a computer works?
▪ Main memory size
- Too little means constant memory swapping
o Slows processing
o Need more memory if processing many programs or large files
▪ CPU speed
- Expressed in hertz (Hz)
- Classified as 32-bit or 64-bit
o Needs more CPU if handling large spreadsheets or database files
▪ Dual processors for PCs
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Bit is either 0 or 1: sizing computer data. Size of main memory and storage devices. How does a computer work: cpu (central processing unit) Transfers program or data from disk to main memory. Moves instruction from main memory via data channel or bus. Has small amount of fast memory called cache: keeps frequently used instructions, large cache makes computer fast, but is expensive, main memory. Contains operating system (os) instructions: operating system (os) Progra(cid:373) that (cid:272)o(cid:374)trols (cid:272)o(cid:373)puter(cid:859)s resour(cid:272)es: memory swapping occurs when the main memory is too small to hold all programs and data. Cpu loads programs from memory in chunks. If none available, the operating system will remove chunk being used and replace with requested data. Why should a manager care how a computer works: main memory size. Too little means constant memory swapping: slows processing, need more memory if processing many programs or large files, cpu speed.
