Some guides from Labmaster from years ago, there is some good info for hacking Master codes for the GBA and other tips. Thanks to Helder for the guides.
Contents
Lesson 1 - What you will need
Lesson 2 - Theory
Lesson 3 - Theory II
Lesson 4 - Let the hacking begin!
Lesson 5 - Making codes
Lesson 6 - More of the simple stuff
Lesson 7 - The significance of bits
Lesson 8 - Why I hate Gameshark
Lesson 9 - Iron Man
Lesson 10 - Slot it in there
Lesson 11 - Just joking (keypad activated codes)
Lesson 12 - The V3 enigma
Lesson 13 - Perfect timing (timing modifiers)
Lesson 14 - Walk through walls part I (simple WTW's)
Lesson 15 - Walk through walls part II (simple WTW's)
Lesson 16 - To the Moon and back
Lesson 17 - Bits and pieces
Lesson 18 - Position it
Lesson 19 - Hidden gems
Lesson 20 - Fire Emblem
Lesson 21 - Character data blocks part I
Lesson 22 - Character data blocks part II
Quick Guide - AR V3 Mastercodes
All tools mentioned can be found here