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Start and end: Interrupts_b0

[NES version, Bank 0]

Name: Interrupts_b0 [Show more] Type: Subroutine Category: Start and end Summary: The IRQ and NMI handler while the MMC1 mapper reset routine is still running
Context: See this subroutine in context in the source code References: This subroutine is called as follows: * Vectors_b0 calls Interrupts_b0
.Interrupts_b0 IF _NTSC RTI ; Return from the IRQ interrupt without doing anything ; ; This ensures that while the system is starting up and ; the ROM banks are in an unknown configuration, any IRQ ; interrupts that go via the vector at $FFFE and any NMI ; interrupts that go via the vector at $FFFA will end up ; here and be dealt with ; ; Once bank 7 is switched into $C000 by the ResetMMC1 ; routine, the vector is overwritten with the last two ; bytes of bank 7, which point to the IRQ routine ENDIF