IOs take 5 time units to complete.

Produce a trace of what would happen when you run these processes:
Process 0
  io
  io_done
  cpu
  io
  io_done
  cpu
  io
  io_done

Process 1
  io
  io_done
  cpu
  cpu
  io
  io_done
  io
  io_done

Important behaviors:
  System will switch when the current process is FINISHED or ISSUES AN IO
  After IOs, the process issuing the IO will run LATER (when it is its turn)

R=READY, C=CPU, I=IO, W=WAITING, D=DONE (CPU = RUN:cpu, IO = RUN:io or RUN:io_done)