Chapter 4-6: Machine Language and Assembly Language

Question 1

The Hack language consists of two generic instructions: an “ “ instruction, also called A-instruction, and a “ “
instruction, also called C -instruction.
Hint: What two things does the computer need to know in order to process the commands? How would a postman know where to send a letter?

Answer 1

Address and compute instructions.

Question 2

Every operation involving a memory location requires two Hack commands: What are they?

Answer 2

One for selecting the address on which we want to operate, and one for specifying the desired operation.

Question 3

The instruction @ 5, which is equivalent to 0000000000000101, causes the computer to do?

Answer 3

To store the binary representation of 5 in the A register.

Question 4

The instruction code is a specification that answers what three questions?

Answer 4

(a) what to compute
(b) where to store the computed value
(c) what to do next?

Question 5

What are the three sources of symbols in a Hack computer?
Hint: It’s Not psuedo code

Answer 5

1. Predefined symbols
2. Label symbols
3. Variable symbols

Question 6

These commands like JMP beginWhile specify only the address of the target location.

Answer 6

Unconditional jump

Question 7

These types of commands must also specify a Boolean condition, expressed in some way. Hint: two words

Answer 7

Conditional jump

Question 8

Every machine language features the means to jump to selected locations in the program, both conditionally and unconditionally. This is called what?

Answer 8

Flow of Control

Question 9

What kind of addressing is this?
In this addressing mode the address of the required memory location is not hard coded into the instruction; instead, the instruction specifies a memory location that holds the required address.

Answer 9

Indirect Addressing

Question 10

What kind of addressing is this?
This form of addressing is used to load constants—namely, load values that appear in the instruction code.

Answer 10

Immediate Addressing

Question 11

What kind of addressing is this?
The most common way to address the memory is to express a specific address or use a symbol that refers to a specific address.

Answer 11

Direct Addressing

Question 12

What two categories do Memory Access commands fall into?

Answer 12

1. Arithmetic and logical commands
2. Load and store commands

Question 13

Since binary codes are rather cryptic, machine languages are normally specified using both “ “ and “ “.

Answer 13

Binary codes and symbolic mnemonics

Question 14

Located in the processor’s immediate proximity, the “ “ serve as a highspeed local memory, allowing the processor to manipulate data and instructions quickly.

Answer 14

registers

Question 15

The “ “ is a device capable of performing a fixed set of elementary operations. These typically include arithmetic and logic operations, memory access operations, and control (also called branching) operations.

Answer 15

Processor, normally called CPU

Question 16

This term refers loosely to the collection of hardware devices that store data and instructions in a computer. What is it?

Answer 16

Memory

Question 17

A “ “ can be viewed as an agreed-upon formalism, designed to manipulate a memory using a processor and a set of registers.

Answer 17

machine language

Question 18

The goal of machine language’s design is “ “ in, and total control of, a given hardware platform.

Answer 18

direct execution

Question 19

Define machine language

Answer 19

Machine language is an agreed-upon formalism, designed to code low-level programs as series of machine instructions.