BRK/RTI PRESERVE SIGNATURE, VECTOR AND STACK-RETURN CYCLES

MOS manual chapter 9 sections 9.5, 9.6 and 9.11 plus Example 9.3 define the interrupt-control schedules. BRK fetches its opcode, reads the PC+1 signature byte, pushes PC+2 high then low, pushes a status copy with break and unused bits set, and reads the IRQ vector low then high.

Raw traces, ROM material, local paths, and personal data are not part of this public record.