NES 2.0 Mapper 516: Difference between revisions

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(Document a few mappers with numbers 256+ already used and discussed on the forum)
 
(→‎Registers: rewrite to explicitly denote register address masks. Defer inner bank documentation to normal MMC3 article.)
 
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==Registers==
==Registers==
===Inner Bank select ($8000-$800E, even)===
Mask: $E011
===Inner Bank data ($8001-$800F, odd)===
* $8000, $8001, $A000, $A001, $C000, $C001, $E000, $E001; addresses where CPU A4 is low: As normal [[MMC3]]. Note that the PRG and CHR banks are limited to a 128 KiB inner bank.
These registers are identical to the respective [[MMC3]] registers, except that only the four lowest PRG, and the seven lowest CHR bank bits are used; in other words, the MMC3 bank registers select only within a 128 KiB inner bank.


===Outer Bank select ($8010-$801F)===
Mask: $8010
The ''address'' being written to selects the outer 128 KiB PRG and CHR banks. A0 and A1 select the outer 128 KiB PRG bank, A2 and A3 select the outer 128 KiB CHR bank.
$8010: A~[1xxx xxxx xxx1 CCPP]
 
                          ||||
===IRQ latch ($C000-$DFFE, even)===
                          ||++-- Select 128 KiB outer PRG bank (i.e. PRG A18 and A17)
===IRQ reload ($C001-$DFFF, odd)===
                          ++---- Select 128 KiB outer CHR bank (i.e. CHR A18 and A17)
===IRQ latch ($C000-$DFFE, even)===
===IRQ reload ($C001-$DFFF, odd)===
===IRQ disable ($E000-$FFFE, even)===
===IRQ enable ($E001-$FFFF, odd)===
These registers are identical to the respective [[MMC3]] registers.


==See also==
==See also==
http://forums.nesdev.org/viewtopic.php?f=3&t=16660
http://forums.nesdev.org/viewtopic.php?f=3&t=16660

Latest revision as of 08:10, 24 December 2017

INES 2.0 Mapper 516 is used for the two Brilliant Com Cocoma Pack cartridges from EduBank. They consist of an MMC3 clone (AX5202P) with an additional PAL.

Registers

Mask: $E011

  • $8000, $8001, $A000, $A001, $C000, $C001, $E000, $E001; addresses where CPU A4 is low: As normal MMC3. Note that the PRG and CHR banks are limited to a 128 KiB inner bank.

Mask: $8010 

$8010: A~[1xxx xxxx xxx1 CCPP]
                         ||||
                         ||++-- Select 128 KiB outer PRG bank (i.e. PRG A18 and A17)
                         ++---- Select 128 KiB outer CHR bank (i.e. CHR A18 and A17)

See also

http://forums.nesdev.org/viewtopic.php?f=3&t=16660

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