diff --git a/src/add-ons/accelerants/nvidia/engine/nv_crtc.c b/src/add-ons/accelerants/nvidia/engine/nv_crtc.c
index 45405b8144..f731aba4e4 100644
--- a/src/add-ons/accelerants/nvidia/engine/nv_crtc.c
+++ b/src/add-ons/accelerants/nvidia/engine/nv_crtc.c
@@ -447,6 +447,10 @@ status_t nv_crtc_dpms(bool display, bool h, bool v)
 		{
 			/* powerup both LVDS (laptop panellink) and TMDS (DVI panellink)
 			 * internal transmitters... */
+			/* note:
+			 * the powerbits in this register are hardwired to the DVI connectors,
+			 * instead of to the DACs! (confirmed NV34) */
+			//fixme...
 			DACW(FP_DEBUG0, (DACR(FP_DEBUG0) & 0xcfffffff));
 			/* ... and powerup external TMDS transmitter if it exists */
 			/* (confirmed OK on NV28 and NV34) */
@@ -463,6 +467,10 @@ status_t nv_crtc_dpms(bool display, bool h, bool v)
 		{
 			/* powerdown both LVDS (laptop panellink) and TMDS (DVI panellink)
 			 * internal transmitters... */
+			/* note:
+			 * the powerbits in this register are hardwired to the DVI connectors,
+			 * instead of to the DACs! (confirmed NV34) */
+			//fixme...
 			DACW(FP_DEBUG0, (DACR(FP_DEBUG0) | 0x30000000));
 			/* ... and powerdown external TMDS transmitter if it exists */
 			/* (confirmed OK on NV28 and NV34) */
diff --git a/src/add-ons/accelerants/nvidia/engine/nv_crtc2.c b/src/add-ons/accelerants/nvidia/engine/nv_crtc2.c
index b9c31cd526..845eef8e59 100644
--- a/src/add-ons/accelerants/nvidia/engine/nv_crtc2.c
+++ b/src/add-ons/accelerants/nvidia/engine/nv_crtc2.c
@@ -430,6 +430,10 @@ status_t nv_crtc2_dpms(bool display, bool h, bool v)
 		{
 			/* powerup both LVDS (laptop panellink) and TMDS (DVI panellink)
 			 * internal transmitters... */
+			/* note:
+			 * the powerbits in this register are hardwired to the DVI connectors,
+			 * instead of to the DACs! (confirmed NV34) */
+			//fixme...
 			DAC2W(FP_DEBUG0, (DAC2R(FP_DEBUG0) & 0xcfffffff));
 			/* ... and powerup external TMDS transmitter if it exists */
 			/* (confirmed OK on NV28 and NV34) */
@@ -446,6 +450,10 @@ status_t nv_crtc2_dpms(bool display, bool h, bool v)
 		{
 			/* powerdown both LVDS (laptop panellink) and TMDS (DVI panellink)
 			 * internal transmitters... */
+			/* note:
+			 * the powerbits in this register are hardwired to the DVI connectors,
+			 * instead of to the DACs! (confirmed NV34) */
+			//fixme...
 			DAC2W(FP_DEBUG0, (DAC2R(FP_DEBUG0) | 0x30000000));
 			/* ... and powerdown external TMDS transmitter if it exists */
 			/* (confirmed OK on NV28 and NV34) */
diff --git a/src/add-ons/accelerants/nvidia/engine/nv_general.c b/src/add-ons/accelerants/nvidia/engine/nv_general.c
index 6a5c819e87..bcb75f1593 100644
--- a/src/add-ons/accelerants/nvidia/engine/nv_general.c
+++ b/src/add-ons/accelerants/nvidia/engine/nv_general.c
@@ -1028,9 +1028,12 @@ static status_t nv_general_bios_to_powergraphics()
 	if (si->ps.secondary_head)
 	{
 		/* switch overlay engine to CRTC1 */
-		/* bit 12: overlay engine,
-		 * bit  8: TVout chip (fixme: or bit 4?),
-		 * bit  4: DDC channel (fixme: or bit 8?) */
+		/* bit 17: GPU FP port #2	(confirmed NV25, NV28, confirmed not on NV34),
+		 * bit 16: GPU FP port #1	(confirmed NV25, NV28, confirmed not on NV34),
+		 * bit 12: overlay engine	(all cards),
+		 * bit  9: TVout chip #2	(confirmed on NV18, NV25, NV28),
+		 * bit  8: TVout chip #1	(all cards),
+		 * bit  4: DDC channel		(all cards) */
 		NV_REG32(NV32_2FUNCSEL) &= ~0x00001000;
 		NV_REG32(NV32_FUNCSEL) |= 0x00001000;
 	}
diff --git a/src/add-ons/accelerants/nvidia/engine/nv_info.c b/src/add-ons/accelerants/nvidia/engine/nv_info.c
index b783786edf..f40d474574 100644
--- a/src/add-ons/accelerants/nvidia/engine/nv_info.c
+++ b/src/add-ons/accelerants/nvidia/engine/nv_info.c
@@ -278,8 +278,18 @@ static void detect_panels()
 	CRTCW(VSYNCE ,(CRTCR(VSYNCE) & 0x7f));
 
 	LOG(2,("INFO: Dumping flatpanel related CRTC registers:\n"));
+	/* info LCD register:
+	 * b7: 1 = stereo view (shutter glasses use)				(all cards),
+	 * b5: 1 = power ext. TMDS (or something)/0 = TVout	use	(?)	(confirmed NV28),
+	 * b4: 1 = power ext. TMDS (or something)/0 = TVout use	(?)	(confirmed NV34),
+	 * b3: 1 = ???												(confirmed NV34),
+	 * b0: 1 = panel enabled/0 = TVout enabled					(all cards). */
 	LOG(2,("CRTC1: LCD register: $%02x\n", CRTCR(LCD)));
+	/* info 0x59 register:
+	 * b0: 1 = enable ext. TMDS clock (DPMS)					(confirmed NV28, NV34). */
 	LOG(2,("CRTC1: register $59: $%02x\n", CRTCR(0x59)));
+	/* info 0x9f register:
+	 * b4: 0 = TVout use (?). */
 	LOG(2,("CRTC1: register $9f: $%02x\n", CRTCR(0x9f)));
 
 	/* detect active slave device (if any) */