CS208 Introduction to Computer Systems
Wednesday, 13 September 2023

+ Memory
- Bits
- Bytes
- Memory = big bunch of bytes with addresses 0, 1, 2,..., 2^N - 1

+ C samples: get out your laptop and play along
- output.c - stdout, stderr, and their command-line friends > and 2>
- strings.c - how are char strings stored in memory?
    - pointers, char *, char [],...
- args.c
- charstar.c
- array2d.c -- grid, grid[j], grid[j][k]

+ Questions
- & in printf? (no)
    int k;
    scanf("%d", &k); // because scanf needs to know where k is in memory

+ Integers (if we have time)
- Base 2 (binary)        111011
- Base 8 (octal)             73
- Base 10 (decimal)          59
- Base 16 (hexadecimal)      3b
- Octal: 3-bit chunks, 0 notation, %o in printf
- Hexadecimal: 4-bit chunks, 0x notation, %x and %X in printf, RGB color representation

+ char, byte, character
- ASCII
- Unicode (much more next week)
- od (Unix command)
- hexdump (Unix command)