Sprinter/mame
2
0
Fork 0
mirror of https://github.com/holub/mame synced 2025-04-21 07:52:35 +03:00
Code Issues Actions 1 Packages Projects Releases Wiki Activity

- Implemented VSYNC height computation difference between the Motorola and the Rockwell devices

Browse Source 
- Since the Commodore 40xx computers program an HSYNC width that extends past the end of
  the scanline, I am clamping it in lack of anything better to do.
This commit is contained in:
Zsolt Vasvari 2008-03-01 02:40:27 +00:00
parent 09bf1cb3e4
commit 875ece67f6
1 changed files with 64 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

75
src/emu/video/mc6845.c
View File

@ -26,11 +26,20 @@
#include "mc6845.h"
#define LOG (0)
#define LOG (1)
/* device types */
enum
{
TYPE_MC6845,
TYPE_R6545
};
struct _mc6845_t
{
int device_type;
running_machine *machine;
const mc6845_interface *intf;
@ -39,7 +48,7 @@ struct _mc6845_t
UINT8 horiz_char_total;
UINT8 horiz_disp;
UINT8 horiz_sync_pos;
UINT8 horiz_sync_width;
UINT8 sync_width;
UINT8 vert_char_total;
UINT8 vert_total_adj;
UINT8 vert_disp;
@ -134,7 +143,7 @@ void mc6845_register_w(mc6845_t *mc6845, UINT8 data)
case 0x00: mc6845->horiz_char_total = data & 0xff; break;
case 0x01: mc6845->horiz_disp = data & 0xff; break;
case 0x02: mc6845->horiz_sync_pos = data & 0xff; break;
case 0x03: mc6845->horiz_sync_width = data & 0x0f; break;
case 0x03: mc6845->sync_width = data & 0xff; break;
case 0x04: mc6845->vert_char_total = data & 0x7f; break;
case 0x05: mc6845->vert_total_adj = data & 0x1f; break;
case 0x06: mc6845->vert_disp = data & 0x7f; break;
@ -160,6 +169,8 @@ static void configure_screen(mc6845_t *mc6845, int postload)
{
if (mc6845->intf)
{
UINT16 hsync_on_pos, hsync_off_pos, vsync_on_pos, vsync_off_pos;
/* compute the screen sizes */
UINT16 horiz_pix_total = (mc6845->horiz_char_total + 1) * mc6845->intf->hpixels_per_column;
UINT16 vert_pix_total = (mc6845->vert_char_total + 1) * (mc6845->max_ras_addr + 1) + mc6845->vert_total_adj;
@ -169,10 +180,27 @@ static void configure_screen(mc6845_t *mc6845, int postload)
UINT16 max_visible_y = mc6845->vert_disp * (mc6845->max_ras_addr + 1) - 1;
/* determine the syncing positions */
UINT16 hsync_on_pos = mc6845->horiz_sync_pos * mc6845->intf->hpixels_per_column;
UINT16 hsync_off_pos = hsync_on_pos + (mc6845->horiz_sync_width * mc6845->intf->hpixels_per_column);
UINT16 vsync_on_pos = mc6845->vert_sync_pos * (mc6845->max_ras_addr + 1);
UINT16 vsync_off_pos = vsync_on_pos + 0x10; /* this is a constant -- non-programmable */
UINT8 horiz_sync_char_width = mc6845->sync_width & 0x0f;
UINT8 vert_sync_pix_height = (mc6845->device_type == TYPE_MC6845) ? 0x10 : (mc6845->sync_width >> 4) & 0x0f;
if (horiz_sync_char_width == 0)
horiz_sync_char_width = 0x10;
if (vert_sync_pix_height == 0)
vert_sync_pix_height = 0x10;
hsync_on_pos = mc6845->horiz_sync_pos * mc6845->intf->hpixels_per_column;
hsync_off_pos = hsync_on_pos + (horiz_sync_char_width * mc6845->intf->hpixels_per_column);
vsync_on_pos = mc6845->vert_sync_pos * (mc6845->max_ras_addr + 1);
vsync_off_pos = vsync_on_pos + vert_sync_pix_height;
/* the Commodore 40xx series computers program a horizontal synch pulse that extends
past the scanline width. I am assume that the real device will clamp it */
if (hsync_off_pos > horiz_pix_total)
hsync_off_pos = horiz_pix_total;
if (vsync_off_pos > vert_pix_total)
vsync_off_pos = vert_pix_total;
/* update only if screen parameters changed, unless we are coming here after loading the saved state */
if (postload ||
@ -184,7 +212,7 @@ static void configure_screen(mc6845_t *mc6845, int postload)
/* update the screen if we have valid data */
if ((horiz_pix_total > 0) && (max_visible_x < horiz_pix_total) &&
(vert_pix_total > 0) && (max_visible_y < vert_pix_total) &&
(hsync_off_pos <= horiz_pix_total) && (vsync_off_pos <= vert_pix_total) &&
(hsync_on_pos <= horiz_pix_total) && (vsync_on_pos <= vert_pix_total) &&
(hsync_on_pos != hsync_off_pos))
{
rectangle visarea;
@ -558,7 +586,7 @@ void mc6845_update(mc6845_t *mc6845, bitmap_t *bitmap, const rectangle *cliprect
/* device interface */
static void *mc6845_start(running_machine *machine, const char *tag, const void *static_config, const void *inline_config)
static void *common_start(running_machine *machine, const char *tag, const void *static_config, const void *inline_config, int device_type)
{
mc6845_t *mc6845;
char unique_tag[30];
@ -572,6 +600,7 @@ static void *mc6845_start(running_machine *machine, const char *tag, const void
mc6845 = auto_malloc(sizeof(*mc6845));
memset(mc6845, 0, sizeof(*mc6845));
mc6845->device_type = device_type;
mc6845->machine = machine;
mc6845->intf = static_config;
@ -597,7 +626,17 @@ static void *mc6845_start(running_machine *machine, const char *tag, const void
mc6845->light_pen_latch_timer = timer_alloc(light_pen_latch_timer_cb, mc6845);
/* register for state saving */
state_save_combine_module_and_tag(unique_tag, "mc6845", tag);
switch (device_type)
{
case TYPE_MC6845:
default:
state_save_combine_module_and_tag(unique_tag, "mc6845", tag);
break;
case TYPE_R6545:
state_save_combine_module_and_tag(unique_tag, "r6545", tag);
break;
}
state_save_register_func_postload_ptr(mc6845_state_save_postload, mc6845);
@ -605,7 +644,7 @@ static void *mc6845_start(running_machine *machine, const char *tag, const void
state_save_register_item(unique_tag, 0, mc6845->horiz_char_total);
state_save_register_item(unique_tag, 0, mc6845->horiz_disp);
state_save_register_item(unique_tag, 0, mc6845->horiz_sync_pos);
state_save_register_item(unique_tag, 0, mc6845->horiz_sync_width);
state_save_register_item(unique_tag, 0, mc6845->sync_width);
state_save_register_item(unique_tag, 0, mc6845->vert_char_total);
state_save_register_item(unique_tag, 0, mc6845->vert_total_adj);
state_save_register_item(unique_tag, 0, mc6845->vert_disp);
@ -623,6 +662,16 @@ static void *mc6845_start(running_machine *machine, const char *tag, const void
return mc6845;
}
static void *mc6845_start(running_machine *machine, const char *tag, const void *static_config, const void *inline_config)
{
return common_start(machine, tag, static_config, inline_config, TYPE_MC6845);
}
static void *r6545_start(running_machine *machine, const char *tag, const void *static_config, const void *inline_config)
{
return common_start(machine, tag, static_config, inline_config, TYPE_R6545);
}
static void mc6845_reset(running_machine *machine, void *token)
{
@ -681,6 +730,10 @@ void r6545_get_info(running_machine *machine, void *token, UINT32 state, devicei
{
/* --- the following bits of info are returned as NULL-terminated strings --- */
case DEVINFO_STR_NAME: info->s = "R6545"; break;
/* --- the following bits of info are returned as pointers to data or functions --- */
case DEVINFO_FCT_START: info->start = r6545_start; break;
default: mc6845_get_info(machine, token, state, info); break;
}
}