insideGadgets

I hope you’ve gotten a feel of how we can access the Gameboy Cartridge in Part 1 and now it’s time for the real part that I was looking forward to: Reading the RAM of the cartridge. Before we start I recommend you read Part 1: Reading the ROM.

In this tutorial I’ll still be using my F1RACE game that uses MBC2 which is actually simpler compared to others because some of the other MBC’s use RAM banking; which is just like ROM banking as you should already know if you read Part 1. I’ll also cover another MBC to show how RAM banking works.

When we want to access the SRAM for reading or writing we firstly have to enable the SRAM, this is done by setting RD/WR and sending a specific command to the MBC. The command is called “initialise MBC” which is found on the VBG website and is given to us as 0x0A, this translates to data pins D1 & D3 should be on (00001010). The other thing to take note of is that RD needs to be set to 1 (off) and WR to be set to 0 (on) when we give the 0x0A command.

(more…)

Read Full Post »

Recently I’ve been collecting retro gaming consoles such as the Gameboy and SNES and whilst playing a game on the SNES I actually lost all my saves when I turned it off (turns out the battery got disconnected from the cartridge). The thought came to me, how can I backup the save game from these devices? There are cart readers around but they seem to be harder to find in this day and age so I thought why not make one myself using the Arduino as it’s so versatile!

Before I begin looking into extracting the save games I’ll look into dumping the ROM which was a way for me to learn how to communicate with the Gameboy cartridge. I’ll now guide you in how to communicate with the Gameboy cartridge to read the ROM so without further delay, let’s begin!

Gameboy Cartridge

Let’s firstly take a look inside a Gameboy cartridge. A typical Gameboy cartridge contains:

• ROM is where the game’s data is stored
• SRAM is where your save games/high scores are keep. Some cartridges (like the one of the left) don’t have this chip because they don’t store any data or it’s built into the MBC
• MBC is the memory bank controller, it allows us switch ROM banks to read the game’s data from the ROM.
• MM1134 IC to control when SRAM should be run from battery or not
• 3v coin cell

(more…)

Read Full Post »

Just a quick post to let you all know that the Standalone Temperature Logger has now been updated to v1.1. This update is for the re-design of the PCB board, it’s now been adjusted so that there are components close to the battery solder joints thus making it easier to solder the battery.

Visit the Standalone Temperature Logger project page to view/download the update.

Read Full Post »

Welcome to Part 9, we have our schematic from Part 7 as below now it’s just time to design and build our PCB. Not a whole lot of content for this post, mostly just pictures.

First thing I did was position the ATtiny85 near the center of the board and position the resistors as close to each other as possible. After that it was just a matter of finding where everything else fit. To make the board as small as possible I decided that I would mount the battery on the back of the board.

(more…)

Read Full Post »