INES Mapper 250: Difference between revisions

Latest revision as of 20:10, 14 April 2023

INES Mapper 250 is a mapper by Nitra, used for pirate games such as Time Diver Avenger and the Queen Bee V.

Hardware consists of regular MMC3 chip connected in different way:

A10 instead of A0 is used to determine which register to write to (i.e. the registers are at $8000, $8400, $A000, $A400, $C000, $C400, $E000, $E400 and their associated
A7..A0 is used instead of D7..D0: the value written to each register is the lower byte of the address (i.e. address AND $00FF), data value is discarded

Queen Bee V contains also 74153 mux which controls PRG-A13 resulting in the following change:

below
$8000 $8000 $a000 $c000 $e000
   0   MMC3  MMC3   0     1

Source: [1]

@@ Line 1: / Line 1: @@
-[[Category:INES Mappers|250]][[Category:MMC3-like mappers]]
+[[Category:INES Mappers|250]][[Category:MMC3-like mappers|250]]
 [[INES Mapper 250]] is a mapper by Nitra, used for pirate games such as [[wikia:c:bootleggames:Time Diver: Avenger|Time Diver Avenger]] and the Queen Bee V.
-FCEUX implements mapper 250 as an MMC3 variant where instead of using the LSB of the address to determine which register to write to, it instead uses the 0x400s bit. (i.e. the registers are at 0x8000,0x8400,0xA000,0xA400, &c and their mirrors)
+Hardware consists of regular MMC3 chip connected in different way:
+* A10 instead of A0 is used to determine which register to write to (i.e. the registers are at $8000, $8400, $A000, $A400, $C000, $C400, $E000, $E400 and their associated
+* A7..A0 is used instead of D7..D0: the value written to each register is the lower byte of the address (i.e. address AND $00FF), data value is discarded
+* Queen Bee V contains also 74153 mux which controls PRG-A13 resulting in the following change:
+ below
+ $8000 $8000 $a000 $c000 $e000
+   MMC3  MMC3   0     1
+Source: [http://krzysiobal.com/carts/?action=search&mpr=250]