Cambridge IGCSE Computer Science
Paper 1
denary number - ANS a base 10 number in which each digit is worth 10 times the digit to its right, and
digits can have 10 values : 0 to 9
right, 16 - ANS hexadecimal number
a base 16 number in which each digit is worth 16 times the digit to its ____________, and digits can
have _____ values : 0 to f
4 - ANS The number of bits needed to store a hexadecimal digit
bit - ANS a single true/false value (short for binary digit)
debug - ANS to find errors in software
digital - ANS any quantity that has a precise, discrete value that can be represented as a number (but
cannot assume a continuous range of values)
byte - ANS a group of 8 bits
nibble - ANS a group of 4 bits (half a byte, equivalent to one hex digit)
kilobyte - ANS 1024 bytes = 2^10 bytes
megabyte - ANS 1024 kilobytes (2^20 or roughly 1 million bytes)
,gigabyte - ANS 1024 megabytes
a,b,c,d,e,f - ANS digits in hexadecimal that are equivalent to 10,11,12,13,14,15
colour, addresses, machine, memory - ANS *uses of hexadecimal numbers*
___________codes in HTML
-Media Access Control (MAC) and IP _____________
-assembly language and ____________ code
_____________ dumps
-specifying memory locations
memory dump - ANS An output of memory contents onto the printer or screen.
Usually represented in hexadecimal.
mark-up language - ANS a language used when processing and presenting text, e.g. HTML.
NOT a programming language but contains information on how text should be structured and presented
(e.g. paragraphs, colour, font, underlining etc.) and can also be used to embed images, hyperlinks etc.
unique, hardware, 48, manufacturer, serial - ANS MAC address
A _______________ identifier number that identifies a device on a local area network (LAN).
The address is typically *static* and set in the ____________ by the manufacturer.
The name is an acronym from *media access control*
,STRUCTURE:
-consists of _____ bits displayed as pairs of hexadecimal.
-The first part is the ____________________ ID, the second part is the ____________ number
digit, parity, repeat - ANS *Methods of data verification*
for short numbers (e.g. credit cards, ISBNs):
-check ____________
for transmission of more data, over a network:
-______________ bit/checks
-checksum
-Automatic _____________ reQuests (ARQ)
repeat reQuest., notification, received, re-sent - ANS Automatic ________________ _____________
(ARQ)
A method of data transmission employing an error-detecting code so that any error detected by the
receiver initiates a repetition of transmission of the incorrectly received message.
The sender also requests a _______________ that the data has been ________________ correctly.
If no delivery notification is received the message is ____________ periodically until either it has been
safely delivered or a time-out is reached.
, Instructions, digital musical instruments, synthesizer - ANS *MIDI (Musical Instrument Digital Interface)*
A set of standards / file format used to represent music in digital form. Used for recording / generating
synthesizers and other digital instruments
MIDI files
• contain _________________ of how to make sound
• Non-audio recording
• File created using ____________ ____________ ________________
• Produced by ____________________
• Used when composing music
• Individual notes/instruments can be changed
sampling rate, sampling resolution, lossy, repeated, indexing - ANS *Sound Sampling*
The _____________ ____________ is the number of times per second the sound wave (i.e. pressure, or
the analogue signal from microphone) is sampled
The ____________ ____________ is the number of discrete levels that the analogue signal is converted
to.
The analogue signal from the microphone must be converted to digital by ADC.
To compress the file by __________ compression, both of these can be reduced.
To compress with lossless compression we could use run-length or Huffman encoding. (i.e. build a table
of ____________ values and represent the data by ___________ into that table
Paper 1
denary number - ANS a base 10 number in which each digit is worth 10 times the digit to its right, and
digits can have 10 values : 0 to 9
right, 16 - ANS hexadecimal number
a base 16 number in which each digit is worth 16 times the digit to its ____________, and digits can
have _____ values : 0 to f
4 - ANS The number of bits needed to store a hexadecimal digit
bit - ANS a single true/false value (short for binary digit)
debug - ANS to find errors in software
digital - ANS any quantity that has a precise, discrete value that can be represented as a number (but
cannot assume a continuous range of values)
byte - ANS a group of 8 bits
nibble - ANS a group of 4 bits (half a byte, equivalent to one hex digit)
kilobyte - ANS 1024 bytes = 2^10 bytes
megabyte - ANS 1024 kilobytes (2^20 or roughly 1 million bytes)
,gigabyte - ANS 1024 megabytes
a,b,c,d,e,f - ANS digits in hexadecimal that are equivalent to 10,11,12,13,14,15
colour, addresses, machine, memory - ANS *uses of hexadecimal numbers*
___________codes in HTML
-Media Access Control (MAC) and IP _____________
-assembly language and ____________ code
_____________ dumps
-specifying memory locations
memory dump - ANS An output of memory contents onto the printer or screen.
Usually represented in hexadecimal.
mark-up language - ANS a language used when processing and presenting text, e.g. HTML.
NOT a programming language but contains information on how text should be structured and presented
(e.g. paragraphs, colour, font, underlining etc.) and can also be used to embed images, hyperlinks etc.
unique, hardware, 48, manufacturer, serial - ANS MAC address
A _______________ identifier number that identifies a device on a local area network (LAN).
The address is typically *static* and set in the ____________ by the manufacturer.
The name is an acronym from *media access control*
,STRUCTURE:
-consists of _____ bits displayed as pairs of hexadecimal.
-The first part is the ____________________ ID, the second part is the ____________ number
digit, parity, repeat - ANS *Methods of data verification*
for short numbers (e.g. credit cards, ISBNs):
-check ____________
for transmission of more data, over a network:
-______________ bit/checks
-checksum
-Automatic _____________ reQuests (ARQ)
repeat reQuest., notification, received, re-sent - ANS Automatic ________________ _____________
(ARQ)
A method of data transmission employing an error-detecting code so that any error detected by the
receiver initiates a repetition of transmission of the incorrectly received message.
The sender also requests a _______________ that the data has been ________________ correctly.
If no delivery notification is received the message is ____________ periodically until either it has been
safely delivered or a time-out is reached.
, Instructions, digital musical instruments, synthesizer - ANS *MIDI (Musical Instrument Digital Interface)*
A set of standards / file format used to represent music in digital form. Used for recording / generating
synthesizers and other digital instruments
MIDI files
• contain _________________ of how to make sound
• Non-audio recording
• File created using ____________ ____________ ________________
• Produced by ____________________
• Used when composing music
• Individual notes/instruments can be changed
sampling rate, sampling resolution, lossy, repeated, indexing - ANS *Sound Sampling*
The _____________ ____________ is the number of times per second the sound wave (i.e. pressure, or
the analogue signal from microphone) is sampled
The ____________ ____________ is the number of discrete levels that the analogue signal is converted
to.
The analogue signal from the microphone must be converted to digital by ADC.
To compress the file by __________ compression, both of these can be reduced.
To compress with lossless compression we could use run-length or Huffman encoding. (i.e. build a table
of ____________ values and represent the data by ___________ into that table
