Sprinter/mame
2
0
Fork 0
mirror of https://github.com/holub/mame synced 2025-07-02 00:29:37 +03:00
Code Issues Actions Packages Projects Releases Wiki Activity

Added option to programatically set the clock pin. This is needed by at least one MESS driver

Browse Source
This commit is contained in:
Zsolt Vasvari 2008-03-22 09:49:45 +00:00
parent a5c8f40a68
commit 8fcc91c77f
2 changed files with 24 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
src/emu/video/mc6845.c
View File

@ -79,6 +79,7 @@ struct _mc6845_t
UINT16 light_pen_addr; /* 0x10/0x11 */ UINT16 light_pen_addr; /* 0x10/0x11 */
/* other internal state */ /* other internal state */
UINT64 clock;
UINT8 register_address_latch; UINT8 register_address_latch;
UINT8 cursor_state; /* 0 = off, 1 = on */ UINT8 cursor_state; /* 0 = off, 1 = on */
UINT8 cursor_blink_count; UINT8 cursor_blink_count;
@ -272,7 +273,7 @@ static void recompute_parameters(mc6845_t *mc6845, int postload)
{ {
rectangle visarea; rectangle visarea;
attoseconds_t refresh = HZ_TO_ATTOSECONDS(mc6845->intf->clock) * (mc6845->horiz_char_total + 1) * vert_pix_total; attoseconds_t refresh = HZ_TO_ATTOSECONDS(mc6845->clock) * (mc6845->horiz_char_total + 1) * vert_pix_total;
visarea.min_x = 0; visarea.min_x = 0;
visarea.min_y = 0; visarea.min_y = 0;
@ -548,6 +549,21 @@ void mc6845_assert_light_pen_input(const device_config *device)
} }
void mc6845_set_clock(const device_config *device, int clock)
{
mc6845_t *mc6845 = get_safe_token(device);
/* validate arguments */
assert(clock > 0);
if (clock != mc6845->clock)
{
mc6845->clock = clock;
recompute_parameters(mc6845, FALSE);
}
}
static void update_cursor_state(mc6845_t *mc6845) static void update_cursor_state(mc6845_t *mc6845)
{ {
/* save and increment cursor counter */ /* save and increment cursor counter */
@ -661,6 +677,9 @@ static void common_start(const device_config *device, int device_type)
assert(mc6845->intf->clock > 0); assert(mc6845->intf->clock > 0);
assert(mc6845->intf->hpixels_per_column > 0); assert(mc6845->intf->hpixels_per_column > 0);
/* copy the initial clock */
mc6845->clock = mc6845->intf->clock;
/* get the screen device */ /* get the screen device */
mc6845->screen = device_list_find_by_tag(device->machine->config->devicelist, VIDEO_SCREEN, mc6845->intf->screen_tag); mc6845->screen = device_list_find_by_tag(device->machine->config->devicelist, VIDEO_SCREEN, mc6845->intf->screen_tag);
assert(mc6845->screen != NULL); assert(mc6845->screen != NULL);
@ -689,6 +708,7 @@ static void common_start(const device_config *device, int device_type)
state_save_register_func_postload_ptr(mc6845_state_save_postload, mc6845); state_save_register_func_postload_ptr(mc6845_state_save_postload, mc6845);
state_save_register_item(unique_tag, 0, mc6845->clock);
state_save_register_item(unique_tag, 0, mc6845->register_address_latch); state_save_register_item(unique_tag, 0, mc6845->register_address_latch);
state_save_register_item(unique_tag, 0, mc6845->horiz_char_total); 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_disp);

3
src/emu/video/mc6845.h
View File

@ -107,6 +107,9 @@ UINT8 mc6845_get_ra(const device_config *device);
/* simulates the LO->HI clocking of the light pen pin (pin 3) */ /* simulates the LO->HI clocking of the light pen pin (pin 3) */
void mc6845_assert_light_pen_input(const device_config *device); void mc6845_assert_light_pen_input(const device_config *device);
/* set the clock (pin 21) of the chip */
void mc6845_set_clock(const device_config *device, int clock);
/* updates the screen -- this will call begin_update(), /* updates the screen -- this will call begin_update(),
followed by update_row() reapeatedly and after all row followed by update_row() reapeatedly and after all row
updating is complete, end_update() */ updating is complete, end_update() */