fn undefined(cpu: &mut Cpu) {
    let pc = cpu.pc().wrapping_sub(1);

    println!("Invalid instruction called at 0x{:04x}. CPU stalled.", pc);

    cpu.set_pc(pc);
}
/// Undefined opcode. Stall the CPU.
Undefined opcode. Stall the CPU.
Undefined opcode . Stall the CPU .
fn undefined(cpu: &mut Cpu) {
    let pc = cpu.pc().wrapping_sub(1);
    println!("Invalid instruction called at 0x{:04x}. CPU stalled.", pc);
    cpu.set_pc(pc);
}
fn undefined ( cpu : & mut Cpu ) { let pc = cpu . pc ( ) . wrapping_sub ( 1 ) ; println ! ( " " pc ) ; cpu . set_pc ( pc ) ; }
Undefined opcode.
Undefined opcode .
cpu
&mut Cpu
cpu
&mut Cpu