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Retron copying mechanism

Retron copying mechanism
by on (#160375)
How does the Retron transfer the ROM from the cart to its internal memory? Specifically, how does it switch banks? Does it use heuristics to figure out the associated mapper and then execute accordingly?
Re: Retron copying mechanism
by on (#160376)
ISTR reading that the Retron 5 (the one that's basically a box containing a kazzo and a ARM-based CPU running emulators) has a mapping of {checksum/hash of some section of CPU memory → mapper #}
Re: Retron copying mechanism
by on (#160378)
lidnariq wrote:
ISTR reading that the Retron 5 (the one that's basically a box containing a kazzo and a ARM-based CPU running emulators) has a mapping of {checksum/hash of some section of CPU memory → mapper #}


That's what I suspected. And, that means the cart will fail to load if the hash is not found in the table.
Re: Retron copying mechanism
by on (#160379)
zeroone wrote:
And, that means the cart will fail to load if the hash is not found in the table.

Yup.
Re: Retron copying mechanism
by on (#160380)
No mapper probing?
Re: Retron copying mechanism
by on (#160393)
Mirroring probing is how the Holy Diver Batman test ROM determines which ASIC mapper it's on. But that can only distinguish mappers with mirroring control, such as MMCs, VRCs, FME-7, the Action 53 mapper, the Holy Diver mapper, and AOROM. Probing can't quite as easily distinguish fixed-mirroring mappers such as GNROM (with subsets NROM and CNROM), BNROM, UNROM, Color Dreams, and Namco 108/MIMIC-1, unless the ROM's structure is known.