INES Mapper 101: Difference between revisions

From NESdev Wiki
Jump to navigationJump to search
(Clean up article and update some info)
 
Line 11: Line 11:
  |||| |||+- (Normal) Low CHR bit
  |||| |||+- (Normal) Low CHR bit
  |||| ||+-- (Normal) High CHR bit
  |||| ||+-- (Normal) High CHR bit
  ++++-++++- (Oversize only) Extra CHR bits
  ++++-++--- (Oversize only) Extra CHR bits




This is the same as J87 but with the bits in order, and so has a better defined [[oversize]] extension; or the same as [[CNROM]] without bus conflicts.
This is the same as J87 but with the bits in order, and so has a better defined [[oversize]] extension; or the same as [[CNROM]] without bus conflicts.

Latest revision as of 10:17, 25 October 2023

This mapper was allocated for a naïve misdumping of the JF-10 board that contains Urusei Yatsura - Lum no Wedding Bell, which assumed the bank bits were reversed. Otherwise, it is entirely identical to J87.

Registers

Bank Select ($6000-$7FFF)

This will select an 8 KB CHR ROM bank for PPU $0000-$1FFF.

7  bit  0
---- ----
CCCC CCHL
|||| ||||
|||| |||+- (Normal) Low CHR bit
|||| ||+-- (Normal) High CHR bit
++++-++--- (Oversize only) Extra CHR bits


This is the same as J87 but with the bits in order, and so has a better defined oversize extension; or the same as CNROM without bus conflicts.