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Last updated on Oct-18-2019 Download

Something confusing about Journey to Silius

Something confusing about Journey to Silius
by on (#88894)
I was thinking about it for a while, but I can't find a suitable answer.
I'm (with 2 other guy) translating "Journey To Silius" to Polish.No, there's no problems, but rather something confusing.
Every 16kb of PRG ROM game repeats 10 bytes.
Code:
FF FF 80 78 EE F2 FF 4C 00 C0 51 C1 F3 FF F3 FF

Hm, last 6 bytes are pointers for NMI,Reset and IRQ.It makes sense to have it in last bank, but why it's also in other banks? What function it can possibly have? It's MMC3 mapper so game can't swap $E000-$FFFF, right? so why have pointers in the end of every 16kb bank?

by on (#88897)
Journey to Silius is MMC1, not MMC3. The game might boot with unknown pages mapped in, so this ensures it can boot no matter what page is mapped in at the beginning.

by on (#88899)
What you noticed is what I've been calling the Barbie stub, after the first game where I saw it in action. It shows up in any mapper that doesn't fix $FFF0-$FFFF, such as any board capable of 32 KiB PRG bankswitching (U*ROM, G*ROM, B*ROM, A*ROM, S*ROM) and the single-game mapper 180 (UNROM modded to fix $8000-$BFFF and allow switching $C000-$FFFF), for exactly the reason Dwedit mentioned. One of the big problems of a multicart builder that I'm working on is how to patch a Barbie stub into each game, even if it uses $FFF0-$FFF9 for something, but I think I've figured it out.

by on (#88930)
Oh, It's MMC1? I don't know why I thought it was MMC3!
Thanks guys and sorry about such silly question.