diff --git a/src/mame/drivers/pgm.c b/src/mame/drivers/pgm.c
index 92081d8f721..db7f07bf55b 100644
--- a/src/mame/drivers/pgm.c
+++ b/src/mame/drivers/pgm.c
@@ -1787,7 +1787,7 @@ ROM_START( pgm3in1 )
 
 	/* No external ARM rom */
 
-	ROM_REGION( 0x480000, "tiles", 0 ) /* 8x8 Text Tiles + 32x32 BG Tiles */
+	ROM_REGION( 0x380000, "tiles", 0 ) /* 8x8 Text Tiles + 32x32 BG Tiles */
 	PGM_VIDEO_BIOS
 	ROM_LOAD( "u5.u5",    0x180000, 0x200000, CRC(da375a50) SHA1(62cd2fd3dfc1897528eaa38d243d7a9526eac71b) )
 
diff --git a/src/mame/machine/pgmprot1.c b/src/mame/machine/pgmprot1.c
index 25d34ad1ddb..89654324432 100644
--- a/src/mame/machine/pgmprot1.c
+++ b/src/mame/machine/pgmprot1.c
@@ -681,6 +681,19 @@ void command_handler_py2k2(pgm_arm_type1_state *state, int pc)
 			state->m_valueresponse = 0x880000;
 			break;
 
+		case 0xcb: // Background layer 'x' select (pgm3in1, same as kov)
+			state->m_valueresponse = 0x880000;
+			state->m_kov_cb_value = state->m_value0;
+		break;
+
+		case 0xcc: // Background layer offset (pgm3in1, same as kov)
+		{
+			int y = state->m_value0;
+			if (y & 0x400) y = -(0x400 - (y & 0x3ff));
+			state->m_valueresponse = 0x900000 + ((state->m_kov_cb_value + (y * 0x40)) * 4);
+		}
+		break;
+
 		case 0x99: // reset?
 			state->m_valuekey = 0x100;
 			state->m_valueresponse = 0x00880000;