notes.txt

https://www.youtube.com/watch?v=uP1gWg5ezyY
opcode is always 8 bits
16 bit address space

p register - processor status register
nv-bdizc
negative
overflow
-
break
decimal
interrupt
zero
carry

stack pointer and program counter are 16 bits
stack pointer first 8 bits are all hard coded to 1 - 00000001

64 kb of address space 0x0000 - 0xffff
first two pages 256 bytes each are special
zero page - 0x0000 - 0x00ff
stack - 0x0100 - 0x01ff (counts down)

instruction types:
- load: lda, ldx, ldy
- store: sta, stx, sty
- transfer between registers: tax, tay, tsx, txa, tya, txs
-alu:
- read modify write, shift
    - rol, ror, asl, lsr
- decrement or increment memory/xyregisters: dec, dex, dey, inc, inx, iny
- addition and subtraction: adc, sbc
- logic: and, ora, eor
- compare: cmp, cpx, cpy
- bit
- set and clear flags: clv, sec, sed, sei, clc, cld, cli
- branch based on flags: bmi, bpl, bvs, bvc, beq, bne, bcs, bcc
- jumping/routines: jmp, jsr, brk, rts, rti
- stack: can only push A register and processor status register: pla, plp, pha, php

addressing modes: (9:25)
- immediate