Testing:
- More tests for branching operations
- More tests for CMP/CPY/CPX operations
- Tests needed for JMP operations
- Tests needed for LD* and ST* operations
- Tests needed for IN* and DE* operations
- Tests needed for T** transfer operations
- Tests needed for interrupt support
- Tests needed for the numerous other operations added
CPU:
- More work on interrupts
- Decimal mode support
- Have each operation return the number of cycles used by the execute function.
- Optimization
Memory:
- Bank wrapping or not wrapping for certain addressing modes and with certain
  settings
- Page wrapping or not wrapping for certain addressing modes and with certain
  settings
- ROM protection
- Improve the memory mapped I/O interface and handling
Display:
- Add the ability to step, pause and stop execution
- Ability to view the path of operation execution as it executes, like have
  the hex chars that are being interpreted at the moment highlighted
- Display a log of the cpu's interpretation process, display what operations
  it finds and what arguments it finds for those operations in the order they
  are executed
- Ability to view what the contents of memory are in a nice fashion
- Ability to change the contents of registers or memory through the user 
  interface
- Ability to load binary files into the emulator through the user interface
- Improve upon the appearance of the interface
- Assembler
- Disassembler