diff --git a/backend/genesys.c b/backend/genesys.c
index ebfde8d87..02abc6335 100644
--- a/backend/genesys.c
+++ b/backend/genesys.c
@@ -782,7 +782,8 @@ sanei_genesys_exposure_time2 (Genesys_Device * dev, float ydpi,
 
   if (exposure < exposure_by_led && dev->model->is_cis)
     exposure = exposure_by_led;
-
+  DBG (DBG_info, "%s: ydpi=%d, step=%d, endpixel=%d led=%d, power=%d => exposure=%d\n",
+       __FUNCTION__, (int)ydpi, step_type, endpixel, led_exposure, power_mode, exposure);
   return exposure;
 }
 
diff --git a/backend/genesys_devices.c b/backend/genesys_devices.c
index eec777d46..3faeb09f8 100644
--- a/backend/genesys_devices.c
+++ b/backend/genesys_devices.c
@@ -763,7 +763,7 @@ static Genesys_Sensor Sensor[] = {
    9*2,
    9*2,
    0,
-   10400, /* up to 5144, 5390, 10264, 20504, 21762 */
+   10304, /* up to 5144, 5390, 10264, 20504, 21762 : capped by max exposure from logs */
    230,
    230,
    {0x00, 0x05, 0x07, 0x09}, /* in fact ,maps to 0x70-0x73 for GL841 */
diff --git a/backend/genesys_gl841.c b/backend/genesys_gl841.c
index 362b54dd5..cb384f764 100644
--- a/backend/genesys_gl841.c
+++ b/backend/genesys_gl841.c
@@ -1644,7 +1644,8 @@ static SANE_Status gl841_write_freq(Genesys_Device *dev, unsigned int ydpi)
 {
 SANE_Status status;
 /**< fast table */
-uint8_t tdefault[] = {0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76 };
+uint8_t tdefault[] = {0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0x36,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xb6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0xf6,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76,0x18,0x76};
+uint8_t t1200[]    = {0xc7,0x31,0xc7,0x31,0xc7,0x31,0xc7,0x31,0xc7,0x31,0xc7,0x31,0xc7,0x31,0xc7,0x31,0xc0,0x11,0xc0,0x11,0xc0,0x11,0xc0,0x11,0xc0,0x11,0xc0,0x11,0xc0,0x11,0xc0,0x11,0xc7,0xb1,0xc7,0xb1,0xc7,0xb1,0xc7,0xb1,0xc7,0xb1,0xc7,0xb1,0xc7,0xb1,0xc7,0xb1,0x07,0xe0,0x07,0xe0,0x07,0xe0,0x07,0xe0,0x07,0xe0,0x07,0xe0,0x07,0xe0,0x07,0xe0,0xc7,0xf1,0xc7,0xf1,0xc7,0xf1,0xc7,0xf1,0xc7,0xf1,0xc7,0xf1,0xc7,0xf1,0xc7,0xf1,0xc0,0x51,0xc0,0x51,0xc0,0x51,0xc0,0x51,0xc0,0x51,0xc0,0x51,0xc0,0x51,0xc0,0x51,0xc7,0x71,0xc7,0x71,0xc7,0x71,0xc7,0x71,0xc7,0x71,0xc7,0x71,0xc7,0x71,0xc7,0x71,0x07,0x20,0x07,0x20,0x07,0x20,0x07,0x20,0x07,0x20,0x07,0x20,0x07,0x20,0x07,0x20};
 uint8_t t300[]     = {0x08,0x32,0x08,0x32,0x08,0x32,0x08,0x32,0x08,0x32,0x08,0x32,0x08,0x32,0x08,0x32,0x00,0x13,0x00,0x13,0x00,0x13,0x00,0x13,0x00,0x13,0x00,0x13,0x00,0x13,0x00,0x13,0x08,0xb2,0x08,0xb2,0x08,0xb2,0x08,0xb2,0x08,0xb2,0x08,0xb2,0x08,0xb2,0x08,0xb2,0x0c,0xa0,0x0c,0xa0,0x0c,0xa0,0x0c,0xa0,0x0c,0xa0,0x0c,0xa0,0x0c,0xa0,0x0c,0xa0,0x08,0xf2,0x08,0xf2,0x08,0xf2,0x08,0xf2,0x08,0xf2,0x08,0xf2,0x08,0xf2,0x08,0xf2,0x00,0xd3,0x00,0xd3,0x00,0xd3,0x00,0xd3,0x00,0xd3,0x00,0xd3,0x00,0xd3,0x00,0xd3,0x08,0x72,0x08,0x72,0x08,0x72,0x08,0x72,0x08,0x72,0x08,0x72,0x08,0x72,0x08,0x72,0x0c,0x60,0x0c,0x60,0x0c,0x60,0x0c,0x60,0x0c,0x60,0x0c,0x60,0x0c,0x60,0x0c,0x60};
 uint8_t t150[]     = {0x0c,0x33,0xcf,0x33,0xcf,0x33,0xcf,0x33,0xcf,0x33,0xcf,0x33,0xcf,0x33,0xcf,0x33,0x40,0x14,0x80,0x15,0x80,0x15,0x80,0x15,0x80,0x15,0x80,0x15,0x80,0x15,0x80,0x15,0x0c,0xb3,0xcf,0xb3,0xcf,0xb3,0xcf,0xb3,0xcf,0xb3,0xcf,0xb3,0xcf,0xb3,0xcf,0xb3,0x11,0xa0,0x16,0xa0,0x16,0xa0,0x16,0xa0,0x16,0xa0,0x16,0xa0,0x16,0xa0,0x16,0xa0,0x0c,0xf3,0xcf,0xf3,0xcf,0xf3,0xcf,0xf3,0xcf,0xf3,0xcf,0xf3,0xcf,0xf3,0xcf,0xf3,0x40,0xd4,0x80,0xd5,0x80,0xd5,0x80,0xd5,0x80,0xd5,0x80,0xd5,0x80,0xd5,0x80,0xd5,0x0c,0x73,0xcf,0x73,0xcf,0x73,0xcf,0x73,0xcf,0x73,0xcf,0x73,0xcf,0x73,0xcf,0x73,0x11,0x60,0x16,0x60,0x16,0x60,0x16,0x60,0x16,0x60,0x16,0x60,0x16,0x60,0x16,0x60};
 
@@ -1655,6 +1656,10 @@ uint8_t *table;
     {
       switch(ydpi)
         {
+          case 3600:
+          case 1200:
+            table=t1200;
+            break;
           case 900:
           case 300:
             table=t300;
@@ -2297,9 +2302,15 @@ gl841_init_optical_regs_scan(Genesys_Device * dev,
       {
 	r = sanei_genesys_get_address (reg, REG6C);
 	if (half_ccd)
-	  r->value &= ~0x80;
+          {
+	    r->value &= ~0x40;
+	    r->value |= 0x20;
+          }
 	else
-	  r->value |= 0x80;
+          {
+	    r->value &= ~0x20;
+	    r->value |= 0x40;
+          }
       }
 
     /* enable shading */
@@ -2693,6 +2704,10 @@ dummy \ scanned lines
       scan_step_type = 1;
   else
       scan_step_type = 2;
+  if (dev->model->motor_type == MOTOR_CANONLIDE80 && yres>=600)
+    {
+      scan_step_type = 1;
+    }
   
 /* exposure_time */
   led_exposure = gl841_get_led_exposure(dev);
@@ -3081,6 +3096,10 @@ dummy \ scanned lines
       scan_step_type = 1;
   else
       scan_step_type = 2;
+  if (dev->model->motor_type == MOTOR_CANONLIDE80 && yres>=600)
+    {
+      scan_step_type = 1;
+    }
   
   led_exposure = gl841_get_led_exposure(dev);
 
@@ -3778,9 +3797,17 @@ gl841_begin_scan (Genesys_Device * dev, Genesys_Register_Set * reg,
 {
   SANE_Status status;
   Genesys_Register_Set local_reg[4];
+  uint8_t val;
 
   DBG (DBG_proc, "gl841_begin_scan\n");
 
+  if (dev->model->gpo_type == GPO_CANONLIDE80)
+    {
+      RIE (sanei_genesys_read_register (dev, REG6B, &val));
+      val = REG6B_GPO18;
+      RIE (sanei_genesys_write_register (dev, REG6B, val));
+    }
+
   local_reg[0].address = 0x03;
   if (dev->model->ccd_type != CCD_PLUSTEK_3600)
     {
@@ -4244,7 +4271,7 @@ gl841_init_regs_for_coarse_calibration (Genesys_Device * dev)
 				 dev->settings.yres,
 				 0,
 				 0,
-				 dev->sensor.optical_res / cksel,
+				 dev->sensor.optical_res / cksel, /* XXX STEF XXX !!! */
 				 20,
 				 16,
 				 channels,