Computer Science - AS Level

Information Representation

2.1 Data Representation / Conversion (Bold links are most important)

• Data Representation / Conversion Presentation
• Binary-Denary Converter1
• Hexadecimal-Denary Converter
  • JK's Binary <-> Denary Converter
  • ASCII (wikibooks)
  • Unicode (wikibooks)
  • BCD (wikipedia)
  • Step by step decimal to binary (vt.edu)
  • Notes for binary & hexadecimal with exercises (wikibooks)
  • Notes on hexadecimal (vt.edu)
  • Binary Revision (youtube.com)
  • Interactive Binary Conversion Game (pwnict)
  • Binary Numbers (csunplugged)
  • Conversion Skills Game (forums.cisco)
    • Conversion Quiz

2.2 Two's Complement & Binary Arithmetic (Bold links are most important)

• Two's Complement & Binary Arithmetic Presentation
• 2's Complement-Decimal Converter2
• How to store negative integers 1 (youtube)
• How to store negative integers 2 (youtube)
• 2's complement (wikibooks)
• 2's complement (courses.cs.vt.edu)
  • Two's complement & Binary Arithmetic Quiz

2.3 Images (Bold links are most important)

• Differences between Bitmaps & Vector Graphics (wikibooks)
• How data for a bitmapped image is encoded (iteach.pk)
• Use the terminology associated with bitmaps:
  • pixel (wikibooks), file header (iteach.pk), image resolution (wikibooks), screen resolution (wikibooks)
• Perform calculations estimating the file size for bitmapped images of different resolutions (iteach.pk)
• How data for a vector graphic is represented and encoded (chesterhouse.co.za)
• Use the terminology associated with vector graphics:
  • drawing object, property and drawing list (wikibooks)
• How typical features found in bitmapped and vector graphics software are used in practice (wikibooks)
• Justify where bitmapped graphics and/or vector graphics are appropriate for a given task (wikibooks)
• Notes from chesterhouse.co.za
• Image Representation (csunplugged)
• Bitmap & Vector Graphics (bbc.co.uk/schools/gcsebitesize)
• Vector VS Bitmap (youtube.com)
• Vector VS Bitmap (adobe.com)
• Bitmap & Vectors (teach-ict.com)
• Bitmap & Vectors (ccm.net)
• Graphics (ict-tuition.co.uk)
  • Images Quiz

2.4 Sound (Bold links are most important)

• How sound is represented and encoded (iteach.pk)
• Use the associated terminology:
  • sampling (teach-ict.com), sampling rate, sampling resolution (wikibooks)
• How file sizes depend on sampling rate and sampling resolution (wikibooks)
• How typical features found in sound-editing software are used in practice (wikipedia)
• Notes and Exercises on Digital Sound Files (wikibooks)
• Audio Editing Software (wikipedia)
• Notes from chesterhouse.co.za
  • Sound Quiz

2.5 Video (Bold links are most important)

• Characteristics of video streams:
  • Frame Rate (frames/second) (teach-ict.com)
  • Interlaced and Progressive Encoding (axis.com)
  • Video Interframe Compression Algorithms & Spatial and Temporal Redundancy (yourdictionary.com)
  • Multimedia Container Formats (wikipedia)
• Background Information on Streaming (wikipedia)
• Video (iteach.pk)
• Interlaced vs. Progressive (animemusicvideos.org)
• Interlaced video (wikipedia)
• Progressive segmented Frame (wikipedia)
• Video Compression (quora.com)
• Data Compression (wikipedia)
• Notes from chesterhouse.co.za

2.6 Compression Techniques (Bold links are most important)

• How digital data can be compressed (howstuffworks), using either ‘lossless’ (teach-ict.com) (including runlength encoding – RLE) (wikipedia) or ‘lossy’ (teach-ict.com) techniques
• Nyquist theorem (wikibooks)
• Advanced Compression (cs4fn)
• Compression Techniques (iteach.pk)
• Notes from chesterhouse.co.za
  • Compression Techniques Quiz