PAG E 5
D E V E L O P M E N T T O O L
U S E R ’ S M A N UA L
PAG E 6
Using Saves From an Emulator
Internal game saves can be used in an
emulator, and vice versa. However, file
naming is very important.
PC emulators such as Project64, Mupen,
1964, etc., generally create their own
save files when they run games that need
them. EEPROM saves can be simply cop-
ied back and forth, if the file names are
what the emulator or 64drive expects.
SRAM and FlashRAM saves tend to be
stored by emulators as little-endian, due
to the heritage of the Intel x86 platform
the emulators were designed for.
64drive saves in the game’s native big-
endian format. So to exchange these you
will have to perform a 32-bit endian swap
on the data.
NES Emulation
While the menu does not directly emulate
anything, it does support automatic load-
ing via an external emulator.
Files with the .NES extension are loaded
via the
Neon64 program, a great achieve-
ment by “hcs”. Download his emulator
and extract the “neon64bu.rom” file to the
memory card’s root directory.
The INES image is automatically placed at
the 2 megabyte offset in SDRAM, and the
emulator loaded at 0x0 before it.
MP3 Playback
While not a supported feature, the menu
has very basic music playback support.
MPEG Audio layer I, II, and III can be
played.
When an image is loaded, playback is
stopped.
Tools
The “64drive_usb” tool is available from
the support website. With it you can trans-
fer your homebrew images to the cartridge
for testing and debugging.
You can also read and write directly to the
USB FIFO using a set of memory mapped
registers.
The specifics are detailed in the separate
Hardware Specification document avail-
able from the support website.
USB Mode
The 64drive has a dedicated USB 2.0 High
Speed FIFO that can be used to:
• Load images into SDRAM
• Select save emulation type
• Upgrade firmware/bootloader
• Do custom communications between
code running on the console and the
PC
How it Works
When the 64drive detects that a USB
cable has been plugged in, it immediately
switches modes.
In this mode,
• Save writebacks are disabled
• Bootloader is disabled
• 64drive appears as a plain cartridge
• USB registers are enabled
When the USB cable is NOT connected,
• Save writebacks are re-enabled
• Bootloader is enabled
This functionality is ideal for development.
Since the bootloader is disabled, you can
reset the console immediately without
corrupting the RDRAM state.
Considerations
Because the bootloader, menu, and by
extension, bootemu are bypassed in
this mode, the header type of the image
you upload
must
match the physical CIC
installed in the 64drive.
For example, with a 6102 installed, you
could load
Super Mario 64, but not 1080
Snowboarding, which uses a 6103 CIC.
Homebrew images can easily be patched
with the proper header type using a hex
editor or the “RN64CRC” tool.
