Sprinter/mame
2
0
Fork 0
mirror of https://github.com/holub/mame synced 2025-04-23 00:39:36 +03:00
Code Issues Actions 1 Packages Projects Releases Wiki Activity

MT #06697 or: How I Learned to Stop Worrying and Love the Odd bit (nw)

Browse Source
This commit is contained in:
angelosa 2017-10-07 03:32:45 +02:00
parent da89d9ee5b
commit 4c913c8641
5 changed files with 13 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
src/devices/video/stvvdp2.cpp
View File

@ -6000,22 +6000,16 @@ uint8_t saturn_state::get_vblank( void )
return 0;
}
// TODO: seabass explicitly wants this bit to be 0 when screen is disabled from bios to game transition, assume following disp bit.
// this is actually wrong for finlarch/sasissu/magzun so it needs to be tested on real HW.
uint8_t saturn_state::get_odd_bit( void )
{
if(STV_VDP2_HRES & 4) //exclusive monitor mode makes this bit to be always 1
return 1;
if(STV_VDP2_LSMD == 0) // same for non-interlace mode
{
if((STV_VDP2_HRES & 1) == 0)
return STV_VDP2_DISP;
return 1;
}
return machine().first_screen()->frame_number() & 1;
// TODO: seabass explicitly wants this bit to be 0 when screen is disabled from bios to game transition.
// But the documentation claims that "non-interlaced" mode is always 1.
// grdforce tests this bit to be 1 from title screen to gameplay, ditto for finlarch/sasissu/magzun.
// Assume documentation is wrong and actually always flip this bit.
return m_vdp2.odd;//machine().first_screen()->frame_number() & 1;
}
int saturn_state::get_vblank_start_position( void )
@ -6205,6 +6199,8 @@ void saturn_state::stv_vdp2_dynamic_res_change( void )
int horz_res,vert_res;
int vres_mask;
// reset odd bit if a dynamic resolution change occurs, seabass ST-V cares!
m_vdp2.odd = 1;
vres_mask = (m_vdp2.pal << 1)|1; //PAL uses mask 3, NTSC uses mask 1
vert_res = d_vres[STV_VDP2_VRES & vres_mask];

1
src/mame/drivers/saturn.cpp
View File

@ -711,6 +711,7 @@ MACHINE_START_MEMBER(sat_console_state, saturn)
save_pointer(NAME(m_scu_regs.get()), 0x100/4);
save_item(NAME(m_en_68k));
save_item(NAME(m_scsp_last_line));
save_item(NAME(m_vdp2.odd));
machine().add_notifier(MACHINE_NOTIFY_EXIT, machine_notify_delegate(&sat_console_state::stvcd_exit, this));

1
src/mame/drivers/stv.cpp
View File

@ -1296,6 +1296,7 @@ MACHINE_START_MEMBER(stv_state,stv)
save_item(NAME(m_port_sel));
save_item(NAME(m_mux_data));
save_item(NAME(m_scsp_last_line));
save_item(NAME(m_vdp2.odd));
stv_register_protection_savestates(); // machine/stvprot.c

1
src/mame/includes/saturn.h
View File

@ -113,6 +113,7 @@ public:
bitmap_rgb32 roz_bitmap[2];
uint8_t dotsel;
uint8_t pal;
uint8_t odd;
uint16_t h_count;
uint16_t v_count;
uint8_t exltfg;

3
src/mame/machine/saturn.cpp
View File

@ -757,6 +757,8 @@ TIMER_DEVICE_CALLBACK_MEMBER(saturn_state::saturn_scanline)
else
m_scu.ist |= (IRQ_VBLANK_IN);
// flip odd bit here
m_vdp2.odd ^= 1;
/* TODO: when Automatic Draw actually happens? Night Striker S is very fussy on this, and it looks like that VDP1 starts at more or less vblank-in time ... */
video_update_vdp1();
}
@ -958,6 +960,7 @@ WRITE_LINE_MEMBER( saturn_state::system_reset_w )
if(!state)
return;
// TODO: actually send a device reset signal to the connected devices
/*Only backup ram and SMPC ram are retained after that this command is issued.*/
memset(m_scu_regs.get() ,0x00,0x000100);
memset(m_sound_ram,0x00,0x080000);