diff --git a/unix/README.md b/unix/README.md
index 9326e18c..a2c122e0 100644
--- a/unix/README.md
+++ b/unix/README.md
@@ -25,6 +25,7 @@ wallet (on testnet, always with the same seed). But there are other options:
 - `-q` => boot and drop into REPL; does nothing else, no setup
 - `-f -w` => boot like a unit that hasn't left factory yet
 - `-p` => pretend we don't know the seed words (xprv import) and so menus are different
+- `-g` => don't skip login sequence
 - `--ms` => define a 2-of-4 multisig wallet, and start off in multisig wallet menu; cosigners are
             "Me", "Myself", "And I" and empty string. BIP45 path.
         - add `--p2wsh` or `--wrap` for the other two address types
@@ -33,7 +34,6 @@ wallet (on testnet, always with the same seed). But there are other options:
 - `--mk3` => emulate mark3 hardware
 - `--mk4` => emulate mark4 hardware
 - `--q1` => emulate Q1 hardware
-- `-g` => don't skip login sequence
 - `--addr` => go to the address explorer at startup
 - `--xw` => go to the wallet export submenu
 - `--paper` => go to the Paper Wallet menu at startup
diff --git a/unix/simulator.py b/unix/simulator.py
index e2b32265..056b3eb3 100755
--- a/unix/simulator.py
+++ b/unix/simulator.py
@@ -89,7 +89,7 @@ class SimulatedScreen:
             self.movie.append((dt, img))
 
     def vsync_handler(self, sr, w):
-        # called at 61Hz, just like the real LCD's TEAR output signal
+        # subclass thing
         return
 
 class LCDSimulator(SimulatedScreen):
@@ -137,6 +137,7 @@ class LCDSimulator(SimulatedScreen):
         self.busy_bar = False
         self.cursor = None
         self.phase = 0
+        self.animate = False
 
         # GPU stuff needs to know implementation details... because it re-implements
         self.COL_BLACK = 0
@@ -146,7 +147,7 @@ class LCDSimulator(SimulatedScreen):
 
     def vsync_handler(self, spriterenderer, window):
         # will be called at 61Hz, just like the real LCD's TEAR output signal
-        if not (self.busy_bar or self.cursor):
+        if not self.animate:
             return
 
         activity = False
@@ -165,6 +166,8 @@ class LCDSimulator(SimulatedScreen):
 
         # maybe save
         if self.movie is not None:
+            # problem: other stuff may be in mid-update; should look at 
+            # time since last save, and if longer than 60Hz, save then?
             self.new_frame()
 
         # draw to screen
@@ -230,7 +233,7 @@ class LCDSimulator(SimulatedScreen):
         cell_w = CELL_W + (CELL_W if dbl_wide else 0)
 
         # make some pixels big enough for either vert or horz lines
-        colour = self.COL_FOREGROUND if phase else self.COL_BLACK
+        colour = self.COL_FOREGROUND if not phase else self.COL_BLACK
 
         def fill_solid(X,Y, w, h, col):
             for x in range(X, X+w):
@@ -359,23 +362,27 @@ class LCDSimulator(SimulatedScreen):
                     for x in range(X, X+w):
                         self.mv[x][y] = px
 
-            elif mode in 'TPBC':
+            elif mode in 'TPBCG':
                 # emulated GPU commands
                 # see vsync_handler() for implementation
                 if mode == 'T':
                     # stop animating: "taking" the SPI bus away from GPU
-                    self.cursor = None
-                    self.busy_bar = False
+                    self.animate = False
+                elif mode == 'G':
+                    # continue animating
+                    self.animate = True
                 elif mode == 'P':
                     # test pattern: a fixed bar code is shown in real deal
                     pass
                 elif mode == 'B':
                     # show busy bar (infinite progress bar)
                     self.busy_bar = True
+                    self.animate = True
                 elif mode == 'C':
                     # show a cursor
                     self.cursor = self.CursorSpec(X,Y, cur_type=w)
                     self.phase = 0      # make update happen immediately
+                    self.animate = True
 
             else:
                 raise ValueError(mode)
diff --git a/unix/variant/gpu.py b/unix/variant/gpu.py
index 0c9bfce2..4e13203b 100644
--- a/unix/variant/gpu.py
+++ b/unix/variant/gpu.py
@@ -24,13 +24,15 @@ class GPUAccess:
     def take_spi(self):
         # stop any on-going animation
         if self.i_have_spi:
-            return
+            return False
         glob.dis.dis.gpu_send('T')
         self.i_have_spi = True
+        return True
 
     def give_spi(self):
-        # not used, implicit in other cmds
-        raise NotImplementedError
+        # continue previously on-going animation
+        self.i_have_spi = False
+        glob.dis.dis.gpu_send('G')
 
     def have_spi(self):
         # do we control the display?
@@ -50,7 +52,7 @@ class GPUAccess:
         self.take_spi()
         
     def cursor_at(self, x, y, cur_type):
-        # use outline to leave most of the cell unaffects (just 1px inside border)
+        # show a cursor, there are several types and sizes
         glob.dis.dis.gpu_send('C', x, y, cur_type)
         self.i_have_spi = False