diff options
Diffstat (limited to 'src/devices/video/stvvdp2.cpp')
-rw-r--r-- | src/devices/video/stvvdp2.cpp | 18 |
1 files changed, 7 insertions, 11 deletions
diff --git a/src/devices/video/stvvdp2.cpp b/src/devices/video/stvvdp2.cpp index 75d8dba5b84..51a7075ce7a 100644 --- a/src/devices/video/stvvdp2.cpp +++ b/src/devices/video/stvvdp2.cpp @@ -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]; |