diff --git a/src/mame/video/seibuspi.cpp b/src/mame/video/seibuspi.cpp
index 78dfa18d159..e393e87b870 100644
--- a/src/mame/video/seibuspi.cpp
+++ b/src/mame/video/seibuspi.cpp
@@ -293,7 +293,7 @@ WRITE32_MEMBER(seibuspi_state::tilemap_dma_start_w)
 	/* fore layer row scroll */
 	if (m_rowscroll_enable)
 	{
-		memcpy(&m_tilemap_ram[0x1800/4], &m_mainram[index], 0x800/4);
+		memcpy(&m_tilemap_ram[0x1800/4], &m_mainram[index], 0x800/4); // 0x2800/4?
 		index += 0x800/4;
 	}
 
@@ -313,7 +313,7 @@ WRITE32_MEMBER(seibuspi_state::tilemap_dma_start_w)
 	/* middle layer row scroll */
 	if (m_rowscroll_enable)
 	{
-		memcpy(&m_tilemap_ram[0x1800/4], &m_mainram[index], 0x800/4);
+		memcpy(&m_tilemap_ram[0x2800/4], &m_mainram[index], 0x800/4); // 0x1800/4?
 		index += 0x800/4;
 	}
 
@@ -764,6 +764,7 @@ void seibuspi_state::video_start()
 	m_midl_layer->set_transparent_pen(63);
 	m_fore_layer->set_transparent_pen(63);
 
+	// TODO : Differs per games?
 	// alpha blending (preliminary)
 	memset(m_alpha_table, 0, 0x2000);