why some multicarts register address is $6000-$7FFF

Discuss hardware-related topics, such as development cartridges, CopyNES, PowerPak, EPROMs, or whatever.

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FlameCyclone
Posts: 15
Joined: Fri Jun 02, 2017 2:45 am

why some multicarts register address is $6000-$7FFF

Post by FlameCyclone » Sat Jul 13, 2019 7:00 pm

Who can help me, I want know why, Is it possible to modify this address?

lidnariq
Posts: 9138
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Location: Seattle

Re: why some multicarts register address is $6000-$7FFF

Post by lidnariq » Sat Jul 13, 2019 7:28 pm

Why? Because not very many games had RAM - it would have made the cartridge more expensive - but the mapper hardware still supported RAM. So it was easy to reuse that space that would have been used by RAM to instead hold a few bits of "outer bank" instead.

Can you change it? Depends on what you mean. The existing mappers are defined by the existing hardware, and you mayn't redefine a them to mean something that doesn't exist. On the other hand, one can modify ("mapper hack") an existing ROM to run on some other mapper that might do what you want instead.

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