Add timing information to all opcodes, and give them some structure.
Add opcodes (but no implementation yet) for all explicit flag modifying commands
Fix opcode table for STA_Abs_Y
Fix LDY_Abs_X to offset the address by X
Implement RTS via FetchVector
Add PHP/PLP
Add missing status flag opcodes
Add BIT, ASL, LSR, ROL, ROR, BVC, BVS, BPL, BMI, NOP
New implementation based on http://www.llx.com/~nparker/a2/opcodes.html
Implement swtichS
Minor touchups
Add unary functions to ALU
Refactor branching structure
Implement unary ALU operations
Reuse unary ALU for some operations on Y
Yet another rewrite with yet another decoding scheme...
Implement JMP, BIT, LDY, STY
Implement stack-manipulating opcodes
Move decoder to separate module
Fix decoding of LDY