Hello! MMC5 has a "Scanline IRQ Status ($5204, read/write)" register, whose reading is defined as:
I looked at the source code of Nintendulator and FCEUX, the "In Frame" flag is cleared in scanline 240 and 241 respectively.
But, the "sprite 0 hit" flag is cleared in scanline 261, the pre-render scanline. If I set a scanline through "IRQ Scanline Compare Value ($5203)" register, obviously the value 261 overflows. So how can I wait for this scanline in MMC5 when I don't have a sprite 0 set?
Thank you!
Code:
7 bit 0---- ----SVxx xxxx MMC5A default power-on value = $00|||+-------- "In Frame" flag+--------- Scanline IRQ Pending flagBut, the "sprite 0 hit" flag is cleared in scanline 261, the pre-render scanline. If I set a scanline through "IRQ Scanline Compare Value ($5203)" register, obviously the value 261 overflows. So how can I wait for this scanline in MMC5 when I don't have a sprite 0 set?
Thank you!
Statistics: Posted by abooge — Sat Mar 30, 2024 4:43 pm — Replies 1 — Views 80