1. COT 4600 Operating Systems Fall 2010
Dan C. Marinescu
Office: HEC 439 B
Office hours: Tu-Th 3:30-4:30 PM

2. Lecture 5 – Tuesday September 7, 2010
Last time:
Complexity of Computer Systems
Resource Sharing and Complexity
Bandwidth and Latency
Iteration
Names and The Basic Abstractions
Today:
HW1 – due.
Discussion of “Hints for Computer Systems Design” by Butler Lampson.
Memory.
Interpreters.
Communication links.
Next time
Communication links
Lecture 5

3. Memory Devices and systems.
Attributes: durability, stability, persistence.
Critical properties of memory systems.
Read-Write coherence.
Before or after atomicity.
Why is it hard to guarantee the critical properties?
Access type: sequential, random.
Access time for a disk.
Types of addressing: location addressing, associative addressing.
RAID 0, 1, 2, 3, 4, 5, and 6.
Lecture 5

4. Interpreters
Active elements. Hardware interpreters; software interpreters
Three abstractions: instruction reference, repertoire, and environment reference.
Flow of control; interrupts.
Processors. Finite-state machine with a number of distinguished initial states.
Layered organization. Example: a calendar program in Java.
Lecture 5

5. Communication links Primitives: send, receive. Wires and networks
The Internet
Internet Core and Edge
Hourglass communication model
Protocol stack
The hardware
Router
Network adaptor
Lecture 5