diff --git a/src/mame/drivers/pgm.c b/src/mame/drivers/pgm.c
index 3f13f5bdaee..0f91f4af88a 100644
--- a/src/mame/drivers/pgm.c
+++ b/src/mame/drivers/pgm.c
@@ -304,14 +304,27 @@ Notes:
 UINT16 *pgm_mainram;
 static void IGS022_reset(running_machine* machine);
 
+static READ16_HANDLER( pgm_videoram_r )
+{
+	pgm_state *state = space->machine->driver_data<pgm_state>();
+
+	if (offset < 0x4000 / 2)
+		return state->bg_videoram[offset&0x7ff];
+	else if (offset < 0x7000 / 2)
+		return state->tx_videoram[offset&0xfff];
+	else
+		return state->videoram[offset];
+}
+
+
 static WRITE16_HANDLER( pgm_videoram_w )
 {
 	pgm_state *state = space->machine->driver_data<pgm_state>();
 
 	if (offset < 0x4000 / 2)
-		pgm_bg_videoram_w(space, offset, data, mem_mask);
+		pgm_bg_videoram_w(space, offset&0x7ff, data, mem_mask);
 	else if (offset < 0x7000 / 2)
-		pgm_tx_videoram_w(space, offset - 0x4000 / 2, data, mem_mask);
+		pgm_tx_videoram_w(space, offset&0xfff, data, mem_mask);
 	else
 		COMBINE_DATA(&state->videoram[offset]);
 }
@@ -572,7 +585,7 @@ static ADDRESS_MAP_START( pgm_mem, ADDRESS_SPACE_PROGRAM, 16)
 //  AM_RANGE(0x900000, 0x903fff) AM_RAM_WRITE(pgm_bg_videoram_w) AM_BASE_MEMBER(pgm_state, bg_videoram) /* Backgrounds */
 //  AM_RANGE(0x904000, 0x905fff) AM_RAM_WRITE(pgm_tx_videoram_w) AM_BASE_MEMBER(pgm_state, tx_videoram) /* Text Layer */
 //  AM_RANGE(0x907000, 0x9077ff) AM_RAM AM_BASE_MEMBER(pgm_state, rowscrollram)
-	AM_RANGE(0x900000, 0x907fff) AM_MIRROR(0x0f8000) AM_RAM_WRITE(pgm_videoram_w) AM_BASE_MEMBER(pgm_state, videoram) /* IGS023 VIDEO CHIP */
+	AM_RANGE(0x900000, 0x907fff) AM_MIRROR(0x0f8000) AM_READWRITE(pgm_videoram_r, pgm_videoram_w) AM_BASE_MEMBER(pgm_state, videoram) /* IGS023 VIDEO CHIP */
 	AM_RANGE(0xa00000, 0xa011ff) AM_RAM_WRITE(paletteram16_xRRRRRGGGGGBBBBB_word_w) AM_BASE_GENERIC(paletteram)
 	AM_RANGE(0xb00000, 0xb0ffff) AM_RAM AM_BASE_MEMBER(pgm_state, videoregs) /* Video Regs inc. Zoom Table */
 
@@ -603,7 +616,7 @@ static ADDRESS_MAP_START( killbld_mem, ADDRESS_SPACE_PROGRAM, 16)
 //  AM_RANGE(0x900000, 0x903fff) AM_RAM_WRITE(pgm_bg_videoram_w) AM_BASE_MEMBER(pgm_state, bg_videoram) /* Backgrounds */
 //  AM_RANGE(0x904000, 0x905fff) AM_RAM_WRITE(pgm_tx_videoram_w) AM_BASE_MEMBER(pgm_state, tx_videoram) /* Text Layer */
 //  AM_RANGE(0x907000, 0x9077ff) AM_RAM AM_BASE_MEMBER(pgm_state, rowscrollram)
-	AM_RANGE(0x900000, 0x907fff) AM_MIRROR(0x0f8000) AM_RAM_WRITE(pgm_videoram_w) AM_BASE_MEMBER(pgm_state, videoram) /* IGS023 VIDEO CHIP */
+	AM_RANGE(0x900000, 0x907fff) AM_MIRROR(0x0f8000) AM_READWRITE(pgm_videoram_r, pgm_videoram_w) AM_BASE_MEMBER(pgm_state, videoram) /* IGS023 VIDEO CHIP */
 	AM_RANGE(0xa00000, 0xa011ff) AM_RAM_WRITE(paletteram16_xRRRRRGGGGGBBBBB_word_w) AM_BASE_GENERIC(paletteram)
 	AM_RANGE(0xb00000, 0xb0ffff) AM_RAM AM_BASE_MEMBER(pgm_state, videoregs) /* Video Regs inc. Zoom Table */
 
@@ -634,7 +647,7 @@ static ADDRESS_MAP_START( olds_mem, ADDRESS_SPACE_PROGRAM, 16)
 //  AM_RANGE(0x900000, 0x903fff) AM_RAM_WRITE(pgm_bg_videoram_w) AM_BASE_MEMBER(pgm_state, bg_videoram) /* Backgrounds */
 //  AM_RANGE(0x904000, 0x905fff) AM_RAM_WRITE(pgm_tx_videoram_w) AM_BASE_MEMBER(pgm_state, tx_videoram) /* Text Layer */
 //  AM_RANGE(0x907000, 0x9077ff) AM_RAM AM_BASE_MEMBER(pgm_state, rowscrollram)
-	AM_RANGE(0x900000, 0x907fff) AM_MIRROR(0x0f8000) AM_RAM_WRITE(pgm_videoram_w) AM_BASE_MEMBER(pgm_state, videoram) /* IGS023 VIDEO CHIP */
+	AM_RANGE(0x900000, 0x907fff) AM_MIRROR(0x0f8000) AM_READWRITE(pgm_videoram_r, pgm_videoram_w) AM_BASE_MEMBER(pgm_state, videoram) /* IGS023 VIDEO CHIP */
 	AM_RANGE(0xa00000, 0xa011ff) AM_RAM_WRITE(paletteram16_xRRRRRGGGGGBBBBB_word_w) AM_BASE_GENERIC(paletteram)
 	AM_RANGE(0xb00000, 0xb0ffff) AM_RAM AM_BASE_MEMBER(pgm_state, videoregs) /* Video Regs inc. Zoom Table */
 
@@ -664,7 +677,7 @@ static ADDRESS_MAP_START( kov2_mem, ADDRESS_SPACE_PROGRAM, 16)
 //  AM_RANGE(0x900000, 0x903fff) AM_RAM_WRITE(pgm_bg_videoram_w) AM_BASE_MEMBER(pgm_state, bg_videoram) /* Backgrounds */
 //  AM_RANGE(0x904000, 0x905fff) AM_RAM_WRITE(pgm_tx_videoram_w) AM_BASE_MEMBER(pgm_state, tx_videoram) /* Text Layer */
 //  AM_RANGE(0x907000, 0x9077ff) AM_RAM AM_BASE_MEMBER(pgm_state, rowscrollram)
-	AM_RANGE(0x900000, 0x907fff) AM_MIRROR(0x0f8000) AM_RAM_WRITE(pgm_videoram_w) AM_BASE_MEMBER(pgm_state, videoram) /* IGS023 VIDEO CHIP */
+	AM_RANGE(0x900000, 0x907fff) AM_MIRROR(0x0f8000) AM_READWRITE(pgm_videoram_r, pgm_videoram_w) AM_BASE_MEMBER(pgm_state, videoram) /* IGS023 VIDEO CHIP */
 	AM_RANGE(0xa00000, 0xa011ff) AM_RAM_WRITE(paletteram16_xRRRRRGGGGGBBBBB_word_w) AM_BASE_GENERIC(paletteram)
 	AM_RANGE(0xb00000, 0xb0ffff) AM_RAM AM_BASE_MEMBER(pgm_state, videoregs) /* Video Regs inc. Zoom Table */
 
@@ -696,7 +709,7 @@ static ADDRESS_MAP_START( cavepgm_mem, ADDRESS_SPACE_PROGRAM, 16)
 	/* 0x880000 - 0x89ffff seems to be protection related, maybe they just happen to access protection results
 	   via a mirror tho. */
 
-	AM_RANGE(0x900000, 0x907fff) AM_MIRROR(0x0f8000) AM_RAM_WRITE(pgm_videoram_w) AM_BASE_MEMBER(pgm_state, videoram) /* IGS023 VIDEO CHIP */
+	AM_RANGE(0x900000, 0x907fff) AM_MIRROR(0x0f8000) AM_READWRITE(pgm_videoram_r, pgm_videoram_w) AM_BASE_MEMBER(pgm_state, videoram) /* IGS023 VIDEO CHIP */
 	AM_RANGE(0xa00000, 0xa011ff) AM_RAM_WRITE(paletteram16_xRRRRRGGGGGBBBBB_word_w) AM_BASE_GENERIC(paletteram)
 	AM_RANGE(0xb00000, 0xb0ffff) AM_RAM AM_BASE_MEMBER(pgm_state, videoregs) /* Video Regs inc. Zoom Table */
 
@@ -828,7 +841,7 @@ static ADDRESS_MAP_START( kovsh_mem, ADDRESS_SPACE_PROGRAM, 16)
 //  AM_RANGE(0x900000, 0x903fff) AM_RAM_WRITE(pgm_bg_videoram_w) AM_BASE_MEMBER(pgm_state, bg_videoram) /* Backgrounds */
 //  AM_RANGE(0x904000, 0x905fff) AM_RAM_WRITE(pgm_tx_videoram_w) AM_BASE_MEMBER(pgm_state, tx_videoram) /* Text Layer */
 //  AM_RANGE(0x907000, 0x9077ff) AM_RAM AM_BASE_MEMBER(pgm_state, rowscrollram)
-	AM_RANGE(0x900000, 0x907fff) AM_MIRROR(0x0f8000) AM_RAM_WRITE(pgm_videoram_w) AM_BASE_MEMBER(pgm_state, videoram) /* IGS023 VIDEO CHIP */
+	AM_RANGE(0x900000, 0x907fff) AM_MIRROR(0x0f8000) AM_READWRITE(pgm_videoram_r, pgm_videoram_w) AM_BASE_MEMBER(pgm_state, videoram) /* IGS023 VIDEO CHIP */
 	AM_RANGE(0xa00000, 0xa011ff) AM_RAM_WRITE(paletteram16_xRRRRRGGGGGBBBBB_word_w) AM_BASE_GENERIC(paletteram)
 	AM_RANGE(0xb00000, 0xb0ffff) AM_RAM AM_BASE_MEMBER(pgm_state, videoregs) /* Video Regs inc. Zoom Table */
 
@@ -943,7 +956,7 @@ static ADDRESS_MAP_START( svg_68k_mem, ADDRESS_SPACE_PROGRAM, 16)
 //  AM_RANGE(0x900000, 0x903fff) AM_RAM_WRITE(pgm_bg_videoram_w) AM_BASE_MEMBER(pgm_state, bg_videoram) /* Backgrounds */
 //  AM_RANGE(0x904000, 0x905fff) AM_RAM_WRITE(pgm_tx_videoram_w) AM_BASE_MEMBER(pgm_state, tx_videoram) /* Text Layer */
 //  AM_RANGE(0x907000, 0x9077ff) AM_RAM AM_BASE_MEMBER(pgm_state, rowscrollram)
-	AM_RANGE(0x900000, 0x907fff) AM_MIRROR(0x0f8000) AM_RAM_WRITE(pgm_videoram_w) AM_BASE_MEMBER(pgm_state, videoram) /* IGS023 VIDEO CHIP */
+	AM_RANGE(0x900000, 0x907fff) AM_MIRROR(0x0f8000) AM_READWRITE(pgm_videoram_r, pgm_videoram_w) AM_BASE_MEMBER(pgm_state, videoram) /* IGS023 VIDEO CHIP */
 	AM_RANGE(0xa00000, 0xa011ff) AM_RAM_WRITE(paletteram16_xRRRRRGGGGGBBBBB_word_w) AM_BASE_GENERIC(paletteram)
 	AM_RANGE(0xb00000, 0xb0ffff) AM_RAM AM_BASE_MEMBER(pgm_state, videoregs) /* Video Regs inc. Zoom Table */
 
diff --git a/src/mame/video/pgm.c b/src/mame/video/pgm.c
index 1005757baab..860ffffe7a9 100644
--- a/src/mame/video/pgm.c
+++ b/src/mame/video/pgm.c
@@ -345,9 +345,9 @@ VIDEO_START( pgm )
 	state->tx_tilemap = tilemap_create(machine, get_pgm_tx_tilemap_tile_info, tilemap_scan_rows, 8, 8, 64, 32);
 	tilemap_set_transparent_pen(state->tx_tilemap, 15);
 
-	state->bg_tilemap = tilemap_create(machine, get_pgm_bg_tilemap_tile_info, tilemap_scan_rows, 32, 32, 64, 64);
+	state->bg_tilemap = tilemap_create(machine, get_pgm_bg_tilemap_tile_info, tilemap_scan_rows, 32, 32, 64, 16);
 	tilemap_set_transparent_pen(state->bg_tilemap, 31);
-	tilemap_set_scroll_rows(state->bg_tilemap, 64 * 32);
+	tilemap_set_scroll_rows(state->bg_tilemap, 16 * 32);
 
 	state->tmppgmbitmap = auto_bitmap_alloc(machine, 448, 224, BITMAP_FORMAT_RGB32);
 
@@ -378,7 +378,7 @@ VIDEO_UPDATE( pgm )
 	tilemap_set_scrolly(state->bg_tilemap,0, state->videoregs[0x2000/2]);
 
 	for (y = 0; y < 224; y++)
-		tilemap_set_scrollx(state->bg_tilemap, (y + state->videoregs[0x2000 / 2]) & 0x7ff, state->videoregs[0x3000 / 2] + state->rowscrollram[y]);
+		tilemap_set_scrollx(state->bg_tilemap, (y + state->videoregs[0x2000 / 2]) & 0x1ff, state->videoregs[0x3000 / 2] + state->rowscrollram[y]);
 
 	{
 		int y, x;