Flashcards
Theory Chapter 1 - Information Representation
Cards in this deck (15)
- 1How to convert from Binary to Denary?multiply the binary value with their place value and add it all up
- 2How to convert from binary to hex?Divide into 4 bit digits/nibble (from the right), each nibble assign with a hex value, add extra 0s if needed
- 3Convert denary to hex?Convert from decimal to binary , then from binary to hex
- 4Convert hex to binary?Assign each hex value (from the right) with a nibble value. Repeat for all hex values, then group together.
- 5hex to decimal?Put hex values into powers of 16 place values, multiply hex values by place values, and add them all together.
- 6Convert a binary into its two's complementFirst turn every 1 in the binary string to a 0 and vice versa, this should give us the binary string’s one’s complement. Then add one to the newly converted string, this will result in 2’s complement
- 7Hexadecimal's values?from 0-9 is 0-9
10 = A
11 = B
12 = C
13 = D
14 = E
15 = F - 8What problems do two's complement resolve?Two’s complement solves the double zero issue and the incorrect mathematics issue.
- 9Convert from two's complement into decimal?Multiply the far left binary digit by its place value and then multiply by -1, then add this onto the denary value of the remainder bits.
e.g. 100101 in 2’s complement is
=(1x32x-1)+(0x16)+(0x8)+(1x4)+(0x2)+(1x1)= -27 in denary. - 10If a far bit left of a two's complement bit pattern is 1 ......the bit pattern represents a negative no.
- 11What is ASCII, it's advantages and disadvantages?American Standard Code for Information Interchange, advantages: takes up little space since it's only storing 8 bits, disadvantages: 128 characters is not enough
- 12What are Unicode?Character system ranging from UTF-8 to UTF-64, with over a million combinations. This, however, leads to more storage space required
- 13What are BCDs?Binary Coded Decimals, taking every decimal digit and turning it into 4 bit pattern.
E.g. 214 = 0010 0001 0100 - 14Packed BCD vs Unpacked BCDUnpacked: 1 decimal digit = 1 byte
Packed: 1 decimal digit = 1 nibble - 15Uses of BCDDue to its simple circuits, BCDs are used for simple maths calculations
Useful for storing date and real-time values, like in the BIOS
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- Advanced Level (A- Level) Computer Science (Information Representation) Flashcards on Theory Chapter 1 - Information Representation, created by TS P on 24/12/2015.
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