anchor.diff:    ;; Main loop - wait for vblank, reset PPU registers, do sprite DMA.
     (with-label :loop
       ;; FIXME: sprite chr table address behaving backward vs what I expect..
  -    (poke #b10000000 *shadow-cr1*)
  -    (poke #b00010100 *shadow-cr2*)
  +    (poke #b10010000 *shadow-cr1*)
  +    (poke #b00011100 *shadow-cr2*)
       (poke 0 *shadow-scroll-x*)
       (poke 0 *shadow-scroll-y*)
   
       (jsr 'reset-sprites)
  +    (poke 40 *sprite-y*)
  +
  +    (poke 20 *sprite-x*)
  +    (jsr '(wiz f 0))
  +
       (poke 40 *sprite-x*)
  -    (poke 80 *sprite-y*)
       (jsr '(sage f 0))
  +
  +    (poke 80 *sprite-x*)
  +    (jsr '(wiz f 0))
   
       (poke 100 *sprite-x*)
       (jsr '(sage f 0))
   
  +
  +    (poke 60 *sprite-y*)
  +
  +    (poke 20 *sprite-x*)
  +    (jsr '(wiz f 0))
  +
  +    (poke 40 *sprite-x*)
  +    (jsr '(sage f 0))
  +
       (poke 80 *sprite-x*)
       (jsr '(wiz f 0))
   
  -    (poke 120 *sprite-x*)
  -    (jsr '(wiz f 0))
  +    (poke 100 *sprite-x*)
  +    (lda (imm 16))
  +    (bita *frame-counter*)
  +    (asif :zero
  +     (jsr '(sage f 0))
  +     :else
  +     (jsr '(sage f 1)))
  +
  +    ;; (poke 120 *sprite-x*)
  +    ;; (jsr '(wiz f 0))
  +
  +
  +
  +    ;; (poke 80 *sprite-y*)
  +
  +    ;; (poke 20 *sprite-x*)
  +    ;; (jsr '(wiz f 0))
  +
  +    ;; (poke 40 *sprite-x*)
  +    ;; (jsr '(sage f 0))
  +
  +    ;; (poke 80 *sprite-x*)
  +    ;; (jsr '(wiz f 0))
  +
  +    ;; (poke 100 *sprite-x*)
  +    ;; (jsr '(sage f 0))
  +
  +    ;; (poke 120 *sprite-x*)
  +    ;; (jsr '(wiz f 0))
  +
  +    ;; (poke 140 *sprite-x*)
  +    ;; (jsr '(wiz f 0))
  +
  +    ;; (poke 160 *sprite-x*)
  +    ;; (jsr '(wiz f 0))
  +
  +    ;; (poke 180 *sprite-x*)
  +    ;; (jsr '(wiz f 0))
   
       (jsr 'end-frame)
   
  
positive.code: (procedure vblank-handler
    (php)
    (inc vblank-flag)
    (plp)
    (rti))
  
  
negative.code: 
  (write-ines "/tmp/sprite1.nes"
              (link *context*)
              :mirror-mode :vertical
              :chr (concatenate 'vector
                                (ichr:encode-chr (ichr:read-gif (asset-path "bg0.gif")))
                                (ichr:encode-chr (ichr:read-gif (asset-path "spr0.gif")))))
  