CS208 Introduction to Computer Systems
Friday, 9 January 2026

+ Quiz on Monday, Jan 12
- bitwise operators (|, &, ~, ^)
- numbers will be represented as hexadecimal
- Example question:

    Given 8-bit numbers a = 0xE5 and b = 0x3C,
    express ~a, a&b, and a|b as 2-digit hexadecimal numbers.

+ Questions

+ Today
- Samples
- Monday's assignment

+ Samples in general
- What should you do when studying one?
    - run it
    - experiment with it
    - read & understand
    - meta-analysi: why is Jeff giving us this sample?
- Pedagogical comments vs. production comments

+ Samples
- args.c
- byte-counter.c
- strings.c
- [if there's time] output.c

=====
#include <stdio.h>

int main() {
    int a = 0xE5;
    int b = 0x3C;

    printf("0x%x\n", a | b);
    printf("0x%x\n", a & b);
    printf("0x%x\n", a ^ b);
    printf("0x%x\n", ~a);

    return 0;
}