NEO mapper/Extension

⚠️ This page is still in the proposal stage and should not yet be considered an official specification.

Proposal for an extension to the NEO mapper format.

Specifications

Principles

Any write operation to the NEO mapper with data bit 7 set to 1 and address bit 0 set to 1 is considered an access to extended features. All other write operations should be considered normal access to the mapper's bank register.

The data contains:

• The number of an extended function in the mapper
• A bit indicating whether the function should be enabled or disabled

The address contains an 8-bit parameter to be passed to the function.

ADDRESS 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 P P P B B 0 0 Parameter 1

DATA 7 6 5 4 3 2 1 0 1 A 0 Function