diff --git a/src/emu/machine/r10788.c b/src/emu/machine/r10788.c
index 7c3984c2823..7e210bc0f9f 100644
--- a/src/emu/machine/r10788.c
+++ b/src/emu/machine/r10788.c
@@ -76,11 +76,6 @@ void r10788_device::device_start()
     save_item(NAME(m_scan_counter));
 
     m_timer = timer_alloc(TIMER_DISPLAY);
-    /* Default clock is from CPU1 */
-    if (clock() == 0)
-    {
-        set_unscaled_clock(machine().firstcpu->clock());
-    }
     m_timer->adjust(clocks_to_attotime(36));
 }
 
diff --git a/src/mame/drivers/gts1.c b/src/mame/drivers/gts1.c
index 0791266dafd..1164eb4de3f 100644
--- a/src/mame/drivers/gts1.c
+++ b/src/mame/drivers/gts1.c
@@ -266,7 +266,7 @@ static MACHINE_CONFIG_START( gts1, gts1_state )
     //MCFG_NVRAM_ADD_0FILL("nvram")
 
     /* General Purpose Display and Keyboard */
-    MCFG_DEVICE_ADD( "r10788", R10788, 0 )
+    MCFG_DEVICE_ADD( "r10788", R10788, XTAL_3_579545MHz / 18 )  // divided in the circuit
     MCFG_R10788_UPDATE( WRITE8(gts1_state,gts1_display_w) )
 
     /* Video */