INES Mapper 101

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Revision as of 07:18, 24 October 2023 by Forple (talk | contribs) (Clean up article and update some info)
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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.