gistfile1.lisp

(defun play-rom (file)
  (reset *nes*)
  (load-rom file)
  (sdl:with-init (sdl:sdl-init-video sdl:sdl-init-audio)
    (sdl:window 256 240 :bpp 24 :sw t)
    (sdl:enable-key-repeat 10 10)
    (sdl:with-events (:poll)
      (:quit-event () t)
      (:key-down-event
       (:key key-pressed)
       (set-key key-pressed *pad* 1))
      (:key-up-event
       (:key key-pressed)
       (set-key key-pressed *pad* 0))
      (:idle ()
             (step-nes 1000)
             (format t "~A~%" (pad-buttons *pad*))
             (format t "~A~%" (incf *counter*))))))

(defun step-nes  (times)
  (with-accessors ((cpu nes-cpu)
                   (ppu nes-ppu)) *nes*
    (dotimes (s times)
       (let ((c-step (step-cpu cpu (get-byte (6502:cpu-pc cpu))))
             (p-step (ppu-step ppu (6502:cpu-cc cpu))))
         (when (ppu-result-vblank p-step)
           (6502:nmi cpu))
         (when (ppu-result-new-frame p-step)
           (sdl:update-display))))))