Chapter 1: Digital Systems and Information Flashcards
How much Volt does an outlet usually use?
110V
How much Volt does a computer usually use?
Up to 1.1V
How much Volt does an iPhone usually use?
Up to 0.8V
How many bits can a modern computer usually process at one time?
64 bit
What does the CPU on a basic level when an user clicks on an image to show it on a device?
The CPU converts the digital info to analog and the device displays the analog image
What is 11010 in decimal?
26
Why is photo editing so taxing on a computer’s CPU?
Because the CPU is making lots of calculations because as the user changes the image, he/she changes the digital information of many pixels
What is 110101.11 in decimal?
53.75
What is an analog signal?
A signal that is continuous as opposed to having only discrete values
What is a digital signal?
A signal that is not continuous across a range of values but that rather has only discrete values that it can take on
What is a bit?
A binary digit (0 or 1)
How do you convert a binary number to a decimal number?
By expanding the number into a power series with a base of 2
In digital systems, we refer to 2 to the power of 10 as what?
K (kilo)
In digital systems, we refer to 2 to the power of 20 as what?
M (mega)
In digital systems, we refer to 2 to the power of 30 as what?
G (giga)
In digital systems, we refer to 2 to the power of 40 as what?
T (tera)
Conventionally people use a kilobit to represent 1000 bits but in reality it is how many bits?
It is actually 2 to the power of 10, which is 1,024 bits
How do you convert a decimal number to a binary number?
By successively dividing by 2 and noting down the remainders. Then, you read the remainders from bottom to top to get the binary number.
The octal number system has which digits?
The digits 0 through 7
How do you convert an octal number to a decimal number?
By expanding the number into a power series with a base of 8
The hexadecimal number system has which digits?
Digits 0 to 9 and A, B, C, D, E, F
How do you convert a hexadecimal number to decimal?
By expanding the number in a power series with a base of 16
How do you convert a binary number to an octal number?
By separating the binary number into groups of three bits each, starting from the decimal point and proceeding to the left and right. Then, you convert each of those triplets into the corresponding number.
How do you convert a binary number to a hexadecimal number?
By separating the binary number into groups of four bits each, starting from the decimal point and proceeding to the left and right. Then, you convert each of those groups of four into the corresponding number.
How do you convert an octal or hexadecimal number to a binary number?
By converting each octal (or hexadecimal) digit to a 3-bit (4-bit) binary equivalent and deleting extra 0s.
What’s the sum of 01100 and 10001?
11101
What’s the sum of 10110 and 10111?
101101
What’s 10110 minus 10010?
00100
What’s 10110 minus 10011?
00011
What is 1011 times 101?
110111
What number system did computers before the early 90s use?
Hexadecimal
How do you convert a decimal number to an octal number?
You successively divide by 8 and note down the remainders. Then, you read the remainders from bottom to top to obtain the octal number.
What does LSB stand for?
Least significant bit
What does MSB stand for?
Most significant bit
What’s the sum of 59F and E46?
13E5
What’s the product of 762 and 45 (both are octal numbers)?
43772
How do you convert decimal fractions to binary?
You successively multiply by 2 and note down the integer parts. Then, you read the integer parts from top to bottom to obtain the binary fraction.
How do you convert decimal fractions to octal?
You successively multiply by 8 and note down the integer parts. Then, you read the integer parts from top to bottom to obtain the binary fraction.
What does BCD stand for?
Binary-coded decimal
What is an advantage and a disadvantage of using BCDs in computers over regular binary numbers?
+: Conversion from decimal to BCD and back is faster
-: BCDs need more bits than its equivalent binary number, which means higher manufacturing costs and more power
What is 185 in BCD?
0001 1000 0101
How do you convert a decimal number to BCD?
For every digit in the decimal number you just use a group of 4 bits to represent each of these digits
The standard binary code for the alphanumeric characters is called what?
American Standard Code for Information Interchange (ASCII)
Why do we use parity bits?
To detect errors in data communication and processing
What is a parity bit?
It is an extra bit that is added to a number to make the total number of 1s either even (even parity) or odd (odd parity)
What is even parity?
Adding an extra parity bit to a number to make the number of 1s even
What is odd parity?
Adding an extra parity bit to a number to make the number of 1s odd
In the case of even parity, how do we figure out that there was an error?
If we get a binary number with an odd number of 1s, then a bit (or an odd number of bits) contained an error
In the case of odd parity, how do we figure out that there was an error?
If we get a binary number with an even number of 1s, then a bit (or an odd number of bits) contained an error
What is Gray code?
It is a binary code, where the number of bit changes from one number to the next is always 1 (as opposed to a varied number in the regular binary code)
Mention the numbers 0 to 7 in a 3-bit Gray code
000
001
011
010
110
111
101
100
