The header will be at 0x7xxx (for LoROM) or 0xFxxx (for HiROM).

xFB0-xFB1 = ID
xFB2      = ?? Unknown, gets compared to 0001
xFC0-xFCF = Title
xFD0-xFD3 = Block Allocation flags (for 32 blocks of 128Kbytes each bit, 32Mbits max)
xFD4-xFD5 = Limited Starts
xFD6     ...

[[!redirects Writing the Header]] Before writing your actual program's code, you need a header to describe WLA the SNES' memorymap. This is basically just a file you will include into your source. It contains all of the basic information about your ROM. The following is a basic header file for a 2 ...

Earlier we made an interrupt table which assigned addresses for the SNES interrupts. We assigned the address to an empty handler that just returned for every interrupt except the NMI (VBLANK) interrupt. This interrupt occurs whenever the T.V.'s tracer is not tracing to the screen, making it safe to ...

[[!include asm_hacking_sidebar]]

Introduction ### {: #introduction}

This document was written for the aspiring ROM hacker with little to no experience in 65c816 programming. The basics have been thoroughly covered and I believe this should prove a significant aid to anyone interested in 65c8 ...

This is a document intended to describe various aspects of SNES timing. It will probably not be useful unless you already know a good bit about the SNES.

BTW, special credit to byuu for the critical observation that the SNES returns to a known timing position on reset. Thus, a deterministic ROM ( ...

Internal Registers

Mnemonic	Friendly Name	Description
A	Accumulator	The accumulator. This is the math register. It stores one of two operands or the result of most arithmetic and logical operations.
X, Y	Index	The i ...

SPC-700

System Overview

CPU

8-bit SPC700, runs at ~1Mhz ...with the effective speed being half (each instruction takes a minimum of 2 cycles)

Memory

64KB (NOT 32KB), shared with everything.

Communication

4 8-bit I/O ports to transfer data to/from the ...