chore: remove Cycle struct and begin scheduler design

src/cpu.rs

@@ -1,10 +1,10 @@
 use crate::apu::Apu;
 use crate::bus::{Bus, BusIo};
-use crate::instruction::cycle::Cycle;
 use crate::instruction::Instruction;
 use crate::interrupt::{InterruptEnable, InterruptFlag};
 use crate::joypad::Joypad;
 use crate::ppu::Ppu;
+use crate::Cycle;
 use bitfield::bitfield;
 use std::fmt::{Display, Formatter, Result as FmtResult};
 
@@ -133,7 +133,7 @@ impl Cpu {
             self.bus.clock();
 
             let elapsed = match kind {
-                ImeEnabled | NonePending => Cycle::new(4),
+                ImeEnabled | NonePending => 4,
                 SomePending => todo!("Implement HALT bug"),
             };
 
@@ -146,11 +146,11 @@ impl Cpu {
         self.handle_ei();
 
         // For use in Blargg's Test ROMs
-        // if self.read_byte(0xFF02) == 0x81 {
-        //     let c = self.read_byte(0xFF01) as char;
-        //     self.write_byte(0xFF02, 0x00);
-        //     eprint!("{}", c);
-        // }
+        if self.read_byte(0xFF02) == 0x81 {
+            let c = self.read_byte(0xFF01) as char;
+            self.write_byte(0xFF02, 0x00);
+            eprint!("{}", c);
+        }
 
         elapsed
     }