NES Dragon Quest (J): lua scripts for memory editing

glitch-load-memory-bizhawk.lua

--[[
Script for Mesen: loads RAM from a file when the glitch is executed.
(just after continuing the message "しのくびかざりが あなたの からだを しめつける。")
--]]

-- NOTE: I recommend to set an absolute path.
local DUMP_PATH = "dump.bin"

local function str_to_bytes(s)
    local bytes = {}

    for i = 1, #s do
        table.insert(bytes, string.byte(s:sub(i, i)))
    end

    return bytes
end

local function load_dump(path)
    local rdr = assert(io.open(path, "rb"))
    local ram_str = rdr:read("*all")
    rdr:close()

    local ram_bytes = str_to_bytes(ram_str)

    for i, b in ipairs(ram_bytes) do
        emu.write(i - 1, b, emu.memType.cpu)
    end
end

local function main()
    local handle = nil

    handle = emu.addMemoryCallback(function (_addr, _value)
        load_dump(DUMP_PATH)
        emu.log("loaded from " .. DUMP_PATH)
        emu.removeMemoryCallback(handle, emu.memCallbackType.cpuExec, 0xBEE3)
    end, emu.memCallbackType.cpuExec, 0xBEE3)
end

main()

glitch-load-memory-fceux.lua

--[[
Script for Mesen: loads RAM to a file when the glitch is executed.
(just after cancelling to drop item)
--]]

-- NOTE: I recommend to set an absolute path.
local DUMP_PATH = "dump.bin"

local function str_to_bytes(s)
    local bytes = {}

    for i = 1, #s do
        table.insert(bytes, string.byte(s:sub(i, i)))
    end

    return bytes
end

local function load_dump(path)
    local rdr = assert(io.open(path, "rb"))
    local ram_str = rdr:read("*all")
    rdr:close()

    local ram_bytes = str_to_bytes(ram_str)

    for i, b in ipairs(ram_bytes) do
        emu.write(i - 1, b, emu.memType.cpu)
    end
end

local function main()
    local handle = nil

    handle = emu.addMemoryCallback(function (_addr, _value)
        load_dump(DUMP_PATH)
        emu.log("loaded from " .. DUMP_PATH)
        emu.removeMemoryCallback(handle, emu.memCallbackType.cpuExec, 0xDE72)
    end, emu.memCallbackType.cpuExec, 0xDE72)
end

main()

glitch-save-memory-bizhawk.lua

--[[
Script for BizHawk: saves RAM to a file when the glitch is executed.
(just after continuing the message "しのくびかざりが あなたの からだを しめつける。")
--]]

-- NOTE: I recommend to set an absolute path.
local DUMP_PATH = "dump.bin"

local function save_dump(path)
    local ram_bytes = mainmemory.read_bytes_as_array(0, 0x800)
    local ram_str = string.char(unpack(ram_bytes))

    local wtr = assert(io.open(path, "wb"))
    wtr:write(ram_str)
    wtr:close()
end

local function main()
    local guid = nil

    guid = event.onmemoryexecute(function (_addr, _val, _flags)
        save_dump(DUMP_PATH)
        print("dumped to " .. DUMP_PATH)
        assert(event.unregisterbyid(guid))
    end, 0xBEE3)
end

main()

glitch-save-memory-fceux.lua

--[[
Script for FCEUX: saves RAM to a file when the glitch is executed.
(just after cancelling to drop item)
--]]

-- NOTE: I recommend to set an absolute path.
local DUMP_PATH = "dump.bin"

local function save_dump(path)
    local ram_str = memory.readbyterange(0, 0x800)

    local wtr = assert(io.open(path, "wb"))
    wtr:write(ram_str)
    wtr:close()
end

local function main()
    memory.registerexec(0xDE72, function (_addr, _size, _value)
        save_dump(DUMP_PATH)
        emu.print("dumped to " .. DUMP_PATH)
        memory.registerexec(0xDE72, nil)
    end)
end

main()