CS208 Introduction to Computer Systems
Wednesday, 29 March 2023

+ Today
- Bits, bytes
- Integers in base 2 (binary), 8 (octal),
    10 (decimal), and 16 (hexadecimal)
- char arrays, strings, and the wild
    proliferation of array notations in C
- pointers, *, &
- Questions
- 2D arrays in C

+ Integer notations [10-12 minutes]
- Binary: relation to physical devices, computational benefits, 0b notation
- Octal: 3-bit chunks, 0 notation, %o
- Hexadecimal: 4-bit chunks, 0x notation, as seen in RGB color representation, %x, %X
- bits, bytes, words
- od (Unix command)
- hexdump (Unix command)

+ Memory
- Big box o' bytes with addresses
- What's the meaning of a byte? Context decides.

+ C strings [10-15 minutes]
- strings.c
- * vs. []
- const

+ Addresses ("pointers") in C
- pointers.c
- &: the "address-of" operator
- * in declarations: "a pointer to"
- * applied to a pointer: "value at this address"
- Array names are pointers. (That doesn't seem fair.)

+ Questions [N minutes]
- "Starting C" assignment
- C in general
- Anything else

+ arrays2d.c
- 2D arrays are simple in C,
    except if you pass them as parameters
    to functions
- row-major order
- grid vs. grid[j] vs. grid[j][k]