iNES Mapper 162 denotes the 外星 (Wàixīng) FS304 circuit board, used for the following games:
A compatible circuit board with an unknown PCB code is used for a few games from 南晶 (Nánjīng):
All registers are initialized to $00 on reset.
Mask: $FF00
D~7654 3210
---------
C... PPpq
| |||+- PRG A15 if $5300.0=1 and $5300.2=1
| ||+-- PRG A16 if $5300.2=1
| ++--- PRG A18..A17
+--------- Automatic 4 KiB CHR-RAM switch: when PPU A13=0 (pattern table) ...
0: CHR A12=PPU A12 (disable auto-switch)
1: CHR A12=PPU A9 latched on last rise of PPU A13 (enable auto-switch)
Automatic 4 KiB CHR-RAM switch means that the left pattern table is used for the the top half of any nametable, and the right pattern table for the bottom half of any nametable, regardless of the scroll position. This auto-switch behavior is similar to that of mapper 96.
Mask: $FF00
D~7654 3210
---------
.... ..p.
+-- PRG A15 if $5300.0=0
Mask: $FF00
D~7654 3210
---------
.... ..PP
++- PRG A20..A19
Mask: $FF00
D~7654 3210
---------
.... .A.B
| +- PRG A15 mode:
| 0: PRG A15=$5100.1
| 1: PRG A15=1 if A=0
| PRG A15=$5000.0 if A=1
+--- PRG A16 mode:
0: PRG A16=1
1: PRG A16=$5000.1
Or in terms of where PRG A15-16 come from:
$5300.2/0 PRG A16 PRG A15
-----------------------------
0.0 1 $5100.1
0.1 1 1
1.0 $5000.1 $5100.1
1.1 $5000.1 $5000.0
Because reset clears all registers' bits, games will boot in 32 KiB PRG-ROM bank #2 (A16=1 and A15=$5100.1=0).
Similar mappers: INES Mapper 163, INES Mapper 164, NES 2.0 Mapper 558
Categories: Mappers using $4020-$5FFF, INES Mappers, Mappers with CHR RAM