INES Mapper 164
iNES Mapper 164 denotes the 燕城 (Yànchéng) cy2000-3 circuit board, used for the following games:
- Final Fantasy 太空戰士 V (G-003)
- 大話西游 (Dàhuà Xīyóu, G-004)
- 櫻桃小丸子 (Chibi Maruku-chan, G-005)
- 岳飛傳 (Yuèfēi Zhuàn, G-006)
- Dark Seed - 黑暗之蛊 (G-009)
- 口袋精靈: 金 (Pokémon: Gold Edition, not to be confused with several similarly-named ports of the same name)
The chipset is also used in the Dongda PEC-9588 Pyramid Educational Computer.
- CPU $6000-$7FFF: 0-8 KiB unbanked PRG-RAM, not battery-backed
- CPU $8000-$BFFF: 16/32 KiB switchable PRG-ROM bank
- PPU $0000-$1FFF: 8 KiB unbanked CHR-RAM
- Nametable mirroring: hard-wired
The circuit board has address lines for 8 KiB of PRG-RAM, though all known carts mount either no or a 2 KiB RAM chip which is then mirrored three times across the respective address range. PRG-RAM is never battery-backed; all games save the game state to a 93C66 512-byte serial EEPROM.
All registers are initialized to $00 on reset.
PRG-ROM Bank Low/1 bpp Mode Switch ($5000, write)
Mask: $FF00 D~7654 3210 --------- CSQM PPPp ||+|-++++- PRG A18..A14 if M=0 || | ++++- PRG A18..A15 if M=1 || +------ PRG banking mode || 0: PRG A14..A18=QPPPp when CPU A14=0 (UxROM, 16 KiB switchable bank) || PRG A14..A18=11111 when CPU A14=1 and S=0 (fixed bank=1F) || PRG A14..A18=111p0 when CPU A14=1 and S=1 (fixed bank=1C or 1E) || 1: PRG A14=CPU A14, PRG A15..A18=PPPp (BxROM, 32 KiB switchable bank) |+-------- See 'M' bit description +--------- 1 bpp video mode: when PPU A13=0 (pattern table) ... 0: CHR A3=PPU A3, CHR A12=PPU A12 (disable 1 bpp mode) 1: CHR A3=PPU A0, CHR A12=PPU A9, both latched on last rise of PPU A13 (enable 1 bpp mode)
- 1 bpp mode is an all points-addressable video mode that allows the 8 KiB CHR-RAM to hold just enough data for an entire screen.
- Because this register is initialized to $00 on reset, thus clearing bit 4 which causes UxROM mode, the game's reset vectors will be at the end of 16 KiB bank #31.
PRG-ROM Bank High ($5100, write)
Mask: $FF00 D~7654 3210 --------- .... ..PP ++- PRG A20..A19
Microwire Interface ($5200, write)
Mask: $FF00 D~7654 3210 --------- ...S .C.D | | +- 93C66 EEPROM DAT output | +--- 93C66 EEPROM CLK output +------ 93C66 EEPROM CS output
Unknown ($5300, write)
All games just write $00 to this register. Its meaning is certainly not the one seen in INES Mapper 162/163.
Microwire Interface ($5500, read)
Mask: $FF00 D~7654 3210 --------- .... .A.. | | +--- 93C66 EEPROM DAT input (inverted)
- NES 2.0 Mapper 558 is a later version which drops UxROM mode and connects the microwire interface to EEPROM differently.