Low level topics

Question 1

What is an opcode

Answer 1

Tha part of a instruction that states which operation should be performed

Question 2

What is ISA

Answer 2

An Instruction Set Architecture (ISA) is part of the abstract model of a computer that defines how the CPU is controlled by the software. The ISA acts as an interface between the hardware and the software, specifying both what the processor is capable of doing as well as how it gets done.

Question 3

What are the most used ISAs

Answer 3

x86 - 32bit (Intel 86)
x86-64 - 64 bit (AMD 64)
ARM
Power Pc

Question 4

What are some Assembly syntax

Answer 4

NASM (Intel)
MASM (Microsoft)
AT & T (Gas)
YASM (NASM + GAS; new rewrite of NASM under BSD license)

Question 5

What are the main three thing that modern computers can do with more instructions

Answer 5

faster versions of something you could
already do
computer security related
hardware interface related

Question 6

What is an OISC

Answer 6

One instruccion set computer

Question 7

Generally, what computations can computers do

Answer 7

Basic integer arithmetic
Memory access
Compare values
Change order of execution based in previous comparison

Question 8

Basic parts of computers are

Answer 8

CPU (Processor)
Working memory
Permanent storage
System bus
Peripherals

Question 9

What is the front bus

Answer 9

Bus with the shortest path to the main working memory (so often called RAM)

Question 10

Bit is the short form of

Answer 10

Binary digit

Question 11

What does mean that a CPU has an 64 architecture

Answer 11

That the system can naturally make operations with 64bits data with one instruction, it does not mean that computers with lower architecture cannot perform operations of numbers with 64bits, but it takes more instructions.

Question 12

Data in memory for audio and text, is diferent?

Answer 12

The whole data indeed is different since has specific information, but every bit is not different of any other byte in memory.

Question 13

Modern computers have groups of bits by sizes, such as

Answer 13

1 byte (8 bits): Typically just referred to as a byte
2 bytes (16 bits): Known as a “word” or a “short”
4 bytes (32 bits): Known as a “double-word” or an “int”
8 bytes (64 bits): Known as a “quadword or long”

But this depends on the system, sometimes 4 bytes are referred as long and 8 bytes as long long.

Question 14

CPU parts

Answer 14

Registers
Control Unit
ALU
Memory management unit
Caches

Question 15

What is the role of control unit

Answer 15

The control unit sets the pacing for the chip. It handles the coordination of all the
different parts of the chip. It handles the clock, which doesn’t tell time, but is more like a
drum beat or a pacemaker—it makes sure that everything operates at the same speed.

Question 16

What is the role of the ALU

Answer 16

The arithmetic and logic unit (ALU) is where the actual processing takes place. It
does the additions, subtractions, comparisons, etc. The ALU is normally wired so that basic
operations can be done with registers extremely quickly (typically in a single clock cycle).

Question 17

What is the role of cache

Answer 17

There are different types of cache, but essentially their role is to save pieces of data that are needed multiple times or is for certain that are going to be accessed next in instructions or by several instructions, so in order to avoid requesting that data from memory, is faster to get it from cache storage.