NES 2.0 Mapper 535 is used for Whirlwind Manu's cartridge conversion (cartrige code LH53) of the Famicom Disk System Game 謎の村雨城 (Nazo no Murasamejō). Its UNIF board name is UNL-LH53.
Mask: probably $F000
D~7654 3210
---------
.... ..E.
+-- 1= Enable counting
Writing to this register acknowledges a pending IRQ, and resets the counter to zero. When counting is enabled, the counter increases on every M2 cycle; upon reaching a value of 7560, an IRQ is generated (according to FCEUX source code).
Mask: probably $F000
Sets the 8 KiB PRG-ROM bank at CPU $6000-$7FFF.
Categories: Mappers with fixed-timing cycle IRQs, FDS conversion mappers