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Diffstat (limited to 'src/devices/video/mc6845.cpp')
-rw-r--r--src/devices/video/mc6845.cpp41
1 files changed, 27 insertions, 14 deletions
diff --git a/src/devices/video/mc6845.cpp b/src/devices/video/mc6845.cpp
index 1e9f7fe7b66..7cec011be11 100644
--- a/src/devices/video/mc6845.cpp
+++ b/src/devices/video/mc6845.cpp
@@ -659,6 +659,28 @@ void mc6845_device::update_upd_adr_timer()
}
+bool mc6845_device::match_line()
+{
+ /* Check if we've reached the end of active display */
+ if ( m_line_counter == m_vert_disp )
+ {
+ m_line_enable_ff = false;
+ m_current_disp_addr = m_disp_start_addr;
+ }
+
+ /* Check if VSYNC should be enabled */
+ if ( m_line_counter == m_vert_sync_pos )
+ {
+ m_vsync_width_counter = 0;
+ m_vsync_ff = 1;
+
+ return true;
+ }
+
+ return false;
+}
+
+
void mc6845_device::handle_line_timer()
{
bool new_vsync = m_vsync;
@@ -698,21 +720,8 @@ void mc6845_device::handle_line_timer()
m_line_counter = ( m_line_counter + 1 ) & 0x7F;
m_line_address = ( m_line_address + m_horiz_disp ) & 0x3fff;
- /* Check if we've reached the end of active display */
- if ( m_line_counter == m_vert_disp )
- {
- m_line_enable_ff = false;
- m_current_disp_addr = m_disp_start_addr;
- }
-
- /* Check if VSYNC should be enabled */
- if ( m_line_counter == m_vert_sync_pos )
- {
- m_vsync_width_counter = 0;
- m_vsync_ff = 1;
-
+ if (match_line())
new_vsync = true;
- }
}
else
{
@@ -731,6 +740,10 @@ void mc6845_device::handle_line_timer()
m_line_counter = 0;
m_line_address = m_disp_start_addr;
m_line_enable_ff = true;
+
+ if (match_line())
+ new_vsync = true;
+
/* also update the cursor state now */
update_cursor_state();