CS208 Introduction to Computer Systems
Monday, 13 April 2026

+ Questions
- do |=, &=, >>=, etc. all work?
    (but not ~=, which is nonsensical)

+ Some clean-up
- Sign extension headaches
    - problem 
       char ch = 0xC3;
       printf("0x%x\n", ch); --> 0xFFFFFFC3
    - printing-bytes.c
    - int x = 0x80000000; x = x >> 4; ...
- What are those Makefiles doing?
- tar files

+ Recap
- bits, bytes
- integer bases: binary, decimal, octal, hexadecimal
- C general structures
- bitwise operators in C: ~, |, &, ^, >>, <<
- byte order ("endianness")
- two's complement representation of integers
- characters: international standards, codepoints, and character encodings

+ Coming up
- programming assignment (Friday 4/17)
- Moodle quiz, take as many times as you want (Sunday 4/19)
- in-class exam (Wednesday 4/22)
    exam study guide, Friday 4/17

+ Pointers
- what's an address?
- C syntax: & to get an address
    int n = 17;
    int *p = &n;

- C syntax: * to mean "pointer to"
    char *s = "cow";

DO NEXT
- read about pointers
- read the pointers.c sample & try it
- read the assignment
- implement get_token_count