INES Mapper 201
iNES Mapper 201 has been assigned to a multicart mapper designed to contain multiple NROM-256 games. It acts like BNROM and CNROM overlaid, where one bank number controls both 32 KiB PRG banks and 8 KiB CHR banks, except it uses the address bus instead of the data bus.
Here are Disch's original notes:
========================
= Mapper 201 =
========================
Example Games:
--------------------------
8-in-1
21-in-1 (2006-CA) (Unl)
Registers:
---------------------------
$8000-FFFF: A~[.... .... RRRR RRRR]
R = PRG/CHR Reg
CHR Setup:
---------------------------
$0000 $0400 $0800 $0C00 $1000 $1400 $1800 $1C00
+---------------------------------------------------------------+
| $8000 |
+---------------------------------------------------------------+
PRG Setup:
---------------------------
$8000 $A000 $C000 $E000
+-------------------------------+
| $8000 |
+-------------------------------+
All known games on this mapper use only the two least significant bits (128KiB PRG / 32KiB CHR).