# Computer Architecture Flashcards Preview

## Computer Science Module 1 > Computer Architecture > Flashcards

Flashcards in Computer Architecture Deck (14)
1
Q

Describe what these types of Registers do.

Register A:

Register B:

Register RO-RN:

Temp Registers:

A

Register A: Accumulator- Operands being manipulated.

Register B: Used as an extension to the A register.

Registers RO-RN: Used by the programs under execution.

Temp Registers: used by the processors operations.

2
Q

Describe what these types of Special Registers do:

Status Flags:

Memory Data Register (MDR):

A

Status Flags: Refers to bits within a special register. Can be set (have a value of 1) to designate a situation. E.g., if the result of an operation was 0, the “Z” flag is set.

Memory Data Register (MDR): Links internal buses to the external Data bus. All data is passing through this register.

3
Q

How do you convert a positive binary to a negative binary using 2’s compliment?

For example: 00010100= 20

A

Find least significant bit (non zero).

00010[1]00

Keep everything up until this bit. But flip the rest.

4
Q

Convert 30 in binary to -30.

A

30 = 00011110

-30= 11100010

5
Q

How would you do a minus sum using binary numbers, one of which being a negative binary number?

A

Add both binary combinations together like normal, but REMOVE any left over remainders!!

6
Q

What is the truth table for NOT? (Boolean algebra).

A

A Ā
0 1
1 0

-One, NOT the other basically.

7
Q

What is the truth table for AND? (Boolean algebra).

A
```A  B  AB
0  0= 0
1   1= 1
1  0= 0
0  1= 0```

Basically, BOTH A AND B must be active.

8
Q

What is the truth table for OR? (Boolean algebra).

A
```A  B  AB
0  0 =0
1  0 =1
0  1 =1
1  1 =0```

One OR the other. OR is exclusive, meaning 1-1 does not activate. XOR is inclusive, meaning 1-1 does activate.

9
Q

What is the truth table for XOR? (Boolean Algebra).

A

0 0 =0
1 0 =1
0 1 =1
1 1 =1

One OR the other, but also BOTH. XOR, unlike OR, is inclusive, meaning 1-1 will activate.

10
Q

Describe the PARALLEL type of I/O.

A
• All data is transferred parallel, at the same time.
• Adapter will channel all bits across I/O at the same time.
• Expensive, very big, so may not fit into some computer systems.
• Very Fast
11
Q

Describe the SERIEL type of I/O

A
• Bits transferred one after the other.
• Adapter will channel all bits across one at a time.
• Slower than parallel.
12
Q

Describe the ANALOGUE type of I/O.

A
• Data is converted from analogue to digital (converted to binary).
• Analogue data is measured in waves, so when being converted, the computer must occasionally test the value of the wave.
• Bigger waves mean more complicated and longer conversions.
• Once analogue data has been measured it vanishes.
13
Q

What is the purpose of the Address Decoder?

A

-Allows addressing of multiple memory and I/O chips but is using a single address to identify both.

14
Q

What does DMAC do?

A

-Facilitates data transfers between I/O chips without involving the processor, this is more efficient.