write and dump a Doctor GB Card with an XG-Writer

[mdmx]

The GB Xchanger and the Doctor GB Card's are still a good choice if you would like to get into GB/C homebrew. Unfortunately the GB Xchanger needs a parallel port and a lot of new computers do not have such a port anymore.

Luckily USB solutions are available. You can find several mods at http://mootan.hg.to
The site is only in Japanese, but Google helped me to translate the page. I had a spare XG-Writer in my collection and so I performed the following mod:
http://mootan.hg.to/fmgbx/ez_fmgbx.html

This is my result:



step by step guide

I used an XG-Writer Advance, model no. XK-GA3120, for this mod.

1) remove old drivers:

First you have to remove the current driver.
- connect XG-Writer to your Computer
- uninstall the driver in the Windows Device Manager
- disconnect XG-Writer
- remove the files XGWInit.sys and XGWriter.sys in C:\Windows\System32\drivers


2) modify XG-Writer:

Game Boy/Color cartridges require 5V, so you have to change the voltage.
- lift GBA pins 1 and 31
- connect GBA pin 1 to transistor IC4 (right pin)
- connect GBA pin 31 to transistor Q1 (left pin)


Now your XG-Writer is GB/C only. Do not insert any GBA cartridges, otherwise it will destroy your GBA carts!


3) install new drivers:

Next you have to install a new driver for the XG-Writer.
- download the driver from http://mootan.hg.to/download/ezusbdrv.zip
- unzip the files
- connect XG-Writer to your Computer
- the Windows wizard for new hardware will pop up
- Don't let Windows search for the driver! Choose that you would like to select your own driver from a list. Then point to the unzipped files and select Cypress EZ-USB.



4) write Doctor GB Card with FlashManager for GBx:

FlashManager for GBx can write and dump your Doctor GB carts. Download the latest version at http://mootan.hg.to/fmgbx/
- when you start the software for the first time, select EZ(XG) Linker (modified) and USB(EZ-USB). A wrong selection may harm your XG-Writer!

- hit START button and the Windows wizard for new hardware will pop up for a second time. Just follow step 3 to finish the installation.
- then press Change CART button in FlashManager and insert your Doctor GB Card
- I would recommend to erase the cart first. Then hit Over Write and select the multiboot file (GBPack)
- Next you can select your games
- hit Append Write to write the files to the cart
- You can also dump GB/C cartridges and backup SRAM


5) additional notes (not verified):

FlashManager for GBx is compatible with the following flash carts:
* DOCTOR GB CARD 64M
* DOCTOR GB CARD 16M
* DOCTOR GB CARD 4M
* GB GAMEJACK 4M
* GB GAMEJACK 64M
* GB Memory Cartridge NP 8M (official Nintendo flash cart)
* 16M Flash Pro for PC-Linker

If you have a cartridge which isn't recognized (e.g. Pocket Camera, GB Gamejack 64M Rumble), then you might get it to work by applying this mod:
- lift GBA pin 2 and connect it trough a 1K ohm resistor to ground (upper left pin of the USB connector).

You can also install a switch, that you can switch between 3,3V (GBA) and 5V (GB/C):
http://mootan.hg.to/fmgbx/ez_fmgbx.html
This method requires that you re-install the drivers everytime you want to switch between GBA and GB/C operation. However if you use a different USB port/hub for GBA and GB/C it might work without re-installation.

You can also apply this modification to an EZ-Flash Writer.