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psikyo/psikyo.cpp: Use accurate measurements for Tengai video timings. (#11100)

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* Measured using a Saleae Logic Pro 16 logic analyzer, sampling at 500Mhz.
* I think the HSync timing specied for Strikers 1945 in the docs is likely incorrect, but I haven't had time to check on my Strikers 1945 board yet.
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buffi 2023-04-13 22:22:50 +02:00 committed by GitHub
parent 17dd927149
commit c6817fd918
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1 changed files with 7 additions and 5 deletions
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src/mame/psikyo/psikyo.cpp
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@ -1174,11 +1174,7 @@ void psikyo_state::s1945(machine_config &config)
/* video hardware */
SCREEN(config, m_screen, SCREEN_TYPE_RASTER);
// TODO: accurate measurements
m_screen->set_refresh_hz(59.9229);
m_screen->set_vblank_time(ATTOSECONDS_IN_USEC(2500));
m_screen->set_size(320, 256);
m_screen->set_visarea(0, 320-1, 0, 256-32-1);
m_screen->set_raw(14.3181_MHz_XTAL / 2, 456, 0, 320, 262, 0, 223); // Approximately 59.923Hz, 39 HSync pulses in VBlank
m_screen->set_screen_update(FUNC(psikyo_state::screen_update));
m_screen->screen_vblank().set(FUNC(psikyo_state::screen_vblank));
@ -1753,6 +1749,12 @@ OSC: 16.000MHz
14.3181MHz
33.8688MHz (YMF)
4.000MHz (PIC)
SYNCS: HSync 15.700kHz, VSync 59.923Hz
HSync most likely derived from 14.3181MHz OSC (divided by 912)
262 lines per frame consisting of:
- Visible lines: 223
- Vertical Back/Front Porch: 16 lines each
- VSync pulse: 7 lines
Chips: PS2001B
PS3103
PS3204