JRBACKUP v1.0b - Coded by Datawiz of BlackBag

Thanks to: LaC, Titanik, Sage, and FoxMcCloud for support and testing.

This little program will allow you to finally backup cartridges
using the v64jr from Bung.  Simply run it from a dos prompt,
and follow the instructions.  One small thing to remember:

                    *** IMPORTANT ***

In order to successfully back up a cartridge, it must be plugged
DIRECTLY into the v64jr.  Be sure to remove ANY device that may
be sitting inbetween the cart and the jr ( DS1, DX256, GameShark,
thermonuclear detonator, etc. ).

This version of the backup rom will ONLY backup cartridges with
"standard" 1st generation bootcodes.  This covers a vast majority
of carts on the market.  The next version will allow backing up
of the "nonstandard" carts (i.e. yoshi, 1080, zelda).  When the
program instructs you to turn on the N64, you should immediately
see the screen turn white.  If you see no such screen, then the
cart is nonstandard.  If the screen turns white, then eventually
turns black again, the program is functioning correctly. woohoo.

If you find a bug or have a problem, you can email me at
datawiz@blackbag.org .  Beware, I have an itchy delete button
finger, so please make your email intelligent.

-------
No N64 Devkits or Libraries were harmed during the programming of this
utility.  It is written in 100% assembly on the N64 side.
-------


To Do List:

. Port to linux
. Support for nonstandard bootcodes
. SRAM/EEPROM backup and restore
. DS1 Management
. Pick up milk, bread, and...errr, wrong list


Technical Notes:

Why must we use the N64 to backup a rom?  Well, because of the way the v64jr
was designed, the Cart is not _directly_ accessable from the PC.  The
v64jr can only map the Cart to the N64 memory space, giving an N64 program
access to the Cart.  To make matters even more complicated, you must use the
PC to tell the v64jr to map the Cart accordingly... :)

Now that you know why the N64 is used to backup the cart, we can now
understand what happens.

PC program tells the JR to map cart to N64 memory, and make DRAM writable
PC program uploads a small N64 rom to the jr -- user turns on N64
    This rom dmas (hardware memory copy) the cart at (starting at 0xb4000000)
    to N64 RDRAM (0x80200000) in 2 megabyte chunks.  Then the N64 program
    dmas the data over to the Jr's DRAM (starting at 0xb0000000).  This
    process continues until the entire rom is copied.
PC program is told that rom backup on the N64 is finished
PC program downloads the rom from the JR to the PC

Now, since using the N64 is how we get a cart backed up, there is a
problem with nonstandard bootcodes in roms.  Unfortunately, there is
no proactive approach to fixing this.  If a new cart comes out, the
only way to back it up on the jr is to copy the bootcode from an
already backed up image.  Then use the bootcode in the backup program.
This is why some carts will not work with this program (1080, Yoshi,
Zelda).

-- Datawiz