User:JuliaFromIT

to-do list

For KS3 Computing Binary page

https://en.wikibooks.org/wiki/KS3_Computing/Binary

1. Look at the sizes available for USB storage devices and SD cards. Notice that they're all powers of two? Why is this?
2. Make an 8 x 8 black and white bitmap, convert each row into a numeric value, send the 8 numbers to a partner and reconstruct each others' bitmaps.
3. Talk about file sizes - 8 x 8 = 8 bytes. What's the screen resolution on this computer? How many colours? How many bytes (kb, mb) is that per frame? What's the resolution and fps for an animated GIF? What's the size of a 10s GIF? What's the resolution and fps for HD video? How much data is 1 min of HD film? And that's just video - there's sound too!
4. Compare to actual sizes of a piece of film on disc - how does AVI compare to MP4? (See compression exercise below for beginning of explanation.)
5. Compare ASCII and Unicode. How many bits for each? How much text is 1Kb? What file size is the complete works of Shakespeare? How many minutes of Romeo and Juliet could you read to MP3 for the same file size?

Extension: rename a word doc's docx file to .zip - open it up and look at what else is in the xml. XML is plain text, so we can work out the size, but then ZIP compresses it...

1. Compression exercise - get a cross-stitch pattern or similar, start to read out the pattern to a partner. Note that most people, instead of saying "red, red, red, red, white, white" will say "four red, two white" - that's (kind of) similar to how JPEG compression works.

1. Using bitwise operators to set/get multiple parameters into a single value e.g a sandwich

Bits 1 and 2: bread type (four options: white, brown, granary, gluten free) Bits 3-5: main filling (eight options: chicken, tuna, ham, cheddar cheese, beef, bacon, cheese and ham, chicken and bacon) (why can't we have tuna and cheese?) Bit 6: toasted? Bit 7: mayo? Bit 8: salad?