Lecture 8

Question 1

Computers cannot run programs expressed with names, they need ot translate the version with names to _______ ______

Answer 1

machine code

Question 2

The translslator from code we can understand to machine code is _____

Answer 2

assembler

Question 3

____ _____ is the discipline devoted to best practices in design and
building of programs

Answer 3

software engineering

Question 4

What are some of the programming best practices

Answer 4

• Write code that is clear and easy to understand
• Comment the code
• Effective use of white space
• Use built-in constants

Question 5

What are the key features of programming

Answer 5

Human readable
-Loop 
-Conditionals (If, then, else)
-Simple operations
 (Give flexibility instead of hard coding)

Question 6

The source code to assembler or machine code is called:

Answer 6

• Compiler if translation done completely before program loaded to run
• Interpreter if translation is done statement by statement as program runs (like DOS based Basic)

Question 7

A Program exists as disk file called a _____ _____

that contains _____ _____

Answer 7

• load module

- executable code

Question 8

_____ _____ is software in a form that can be run on a computer. It typically refers to machine language

Answer 8

Executable code

Question 9

A _____ loads the load modules into memory

Answer 9

loader

Question 10

A ____ job is to resolve undefined references in code by linking library object code with our newly created object code

Answer 10

linker

Question 11

What are the different kinds of load modules

Answer 11

• Absolute Loading
• Relocatable Loading
• Dynamic Run-Time Loading

Question 12

What is the problem with absolute loading

Answer 12

associated (bound ) a real memory address to variables, targets at compile
time

Question 13

What is the problem with relocatable loading?

Answer 13

associated (bound) a real memory address to variables, targets at load
time (can’t swap)

Question 14

Dynamic run time loading works by

Answer 14

delay that association (binding) until run-time (requires DAT)

Question 15

There are two ways to link .

Answer 15

Static: Appended to generated code
Dynamic: called at either load time or run time.

Question 16

Magnetic disk

Answer 16

Have > 1 disk coaded with magnetic material (mylar or aluminum)
Disk rotates on center axis
Head is fixed onto arm

Question 17

How much does each sector hold?

Answer 17

512 bytes of data

Question 18

Hard disk can have multiple ____ per spindle

Answer 18

Platters:
 and use both top and bottom surfaces of each platter
 with multiple heads between platters

Question 19

Data rate of 3600 RPM disk is:

Answer 19

1. 80 Mbytes per second (per surface)

- But head has to be in right place

Question 20

Move a disk ____ is called a see

Answer 20

head

Question 21

What is the average latency to access data:

Answer 21

average seek time + average rotational delay

Question 22

There are two types of disk spin we need to be aware of:

Answer 22

• Constant angular velocity disc (track size decreased towards center)
• Constant linear velocity disc (track size constant)

Question 23

Solid state disk remove two delays

Answer 23

rotational delay and seek delay are both gone

Question 24

Solid state disk suffer from the fact that cells can’t be overwritten instead you must

Answer 24

Write new data to new sector than erase old data (garbage collection)

Question 25

What are the two main standards today for disk controller

Answer 25

SCSI and SATA

Question 26

The operating system does not talk directly to disk, instead it talks to ____

Answer 26

controller