Gameboy DMG-01 VGA Adapter

This is the project that the DE0 Digital IO Wing is for. I will use the IO wing to level shift the signals from the Gameboy’s LCD screen so my DE0 can capture the data. The Gameboy is a 5V device and the DE0 does not have 5V tolerant IO. I am using a SN74LVC8T245PWR 8-bit directional level shifter to do the translation on the IO wing board.

Gameboy DMG-01
Gameboy DMG-01.

Purchased a Gameboy DMG-01 off eBay for $20. Needed some cleaning but it worked and had the battery cover!

Taking apart the Gameboy DMG-01.
Taking apart the Gameboy DMG-01.

The Gameboy DMG-01 uses triwing screws. Kidna like philips heads but with 3 “wings” instead of 4. Tool can be found on eBay or Amazon.

Front board and LCD connector for the Gameboy DMG-01.
Front board and LCD connector for the Gameboy DMG-01.

The connector between the front and back of the Gameboy is where I will tap into the signals to sneak a peak. Pinout is the following

Pin 12 – V-Sync
Pin 14 – Pixel Clock
Pin 15 – LCD Data 0
Pin 16 – LCD Data 1
Pin 17 – H-Sync
Pin 21 – Ground

V-Sync should be 60Hz, Pixel Clock 4Mhz, and H-Sync 9.2kHz.

Wires to sniff the connector.
Wires to sniff the connector.
Open Bench Logic Sniffer connected to Gameboy DMG-01.
Open Bench Logic Sniffer connected to Gameboy DMG-01.

Connected up the Open Bench Logic Sniffer and powered up the Gameboy with a game in it then ran the capture. I had the trigger set to wait for the V-Sync signal.

Entire V-Sync frame. Hard to see much detail.
Entire V-Sync frame. Hard to see much detail.
Frame zoomed in a bit to see the individual horizontal lines.
Frame zoomed in a bit to see the individual horizontal lines.
Complete horizontal frame.
Complete horizontal frame.

Then using my DE0_VGA_Driver I started writing the code take data from RAM on the FPGA and output it on the VGA monitor. I wrote a bitmap to .mif format (memory initialization file) convertor to display some Gameboy screenshots on the VGA Monitor. Link to that repo is here.

Gameboy DMG-01 screenshot displayed from DE0 FPGA RAM. Simulating original Gameboy "yellow-green" pallet.
Gameboy DMG-01 screenshot displayed from DE0 FPGA RAM. Simulating original Gameboy “yellow-green” pallet.
Gameboy DMG-01 screenshot displayed from DE0 FPGA RAM. Using B/W color scheme.
Gameboy DMG-01 screenshot displayed from DE0 FPGA RAM. Using B/W color scheme.

Currently working on getting the SN74LVC8T245PWR level shifters working and I will be able to pull live data from the Gameboy LCD data bus.

Categories: Gameboy DMG-01 VGA