Rom dumping over audio
Posted: Mon Aug 25, 2014 7:50 am
Let me begin by stating that this is isn't a finished product and I wouldn't advice anyone to use this in its current state to create a backup archive of their games. What I want to show here is a mess that I hacked together until it finally worked.
Link to the files
What is it?
It's a method to dump cartridges with just the following equipment:
- Mega Drive
- Flash Cartridge (I've used an EverDrive)
- Stereo Recording device (PC)
How does it work?
You plug in the flash cartridge with the dumping programm, start the mega drive, start the dumping programm, pull out the flash cartridge, insert the cartridge that is meant to be dumped, start the recording and press c.
What happens is that the code of the dumping programm is copied into ram and the 68k jumps into ram, thus not more depending on the flas cartridge to run the code. As soon as c is pressed on the controller, the code starts reading the cartridge that is currently inside the cartridge port, and outputting the data in 2-bit samples on both channels.
And it works?
Yes, I've successfully dumped "the ottifants" to test if it works:
Are there any Problems?
Yes.
1. It's currently only tested with 96000hz sampling rate recording and I doubt it currently works with 44100hz.
2. It's a bit slow, taking ~22 minutes to record 1mb of data.
3. Currently the conversion tool is pretty bad and relies on a number of fixed constants. This should be changed where possible to make it more usable for different people.
4. Due to a tiny bug, the dumping rom will leave a tail on the last sample, which the conversion tool might recognize as further bytes. These bytes can be removed in a hex editor to create a clean dump.
5. The current rom is hardcoded to dump 1mb.
This is not meant to help illegal rom spreading.
Link to the files
What is it?
It's a method to dump cartridges with just the following equipment:
- Mega Drive
- Flash Cartridge (I've used an EverDrive)
- Stereo Recording device (PC)
How does it work?
You plug in the flash cartridge with the dumping programm, start the mega drive, start the dumping programm, pull out the flash cartridge, insert the cartridge that is meant to be dumped, start the recording and press c.
What happens is that the code of the dumping programm is copied into ram and the 68k jumps into ram, thus not more depending on the flas cartridge to run the code. As soon as c is pressed on the controller, the code starts reading the cartridge that is currently inside the cartridge port, and outputting the data in 2-bit samples on both channels.
And it works?
Yes, I've successfully dumped "the ottifants" to test if it works:
Are there any Problems?
Yes.
1. It's currently only tested with 96000hz sampling rate recording and I doubt it currently works with 44100hz.
2. It's a bit slow, taking ~22 minutes to record 1mb of data.
3. Currently the conversion tool is pretty bad and relies on a number of fixed constants. This should be changed where possible to make it more usable for different people.
4. Due to a tiny bug, the dumping rom will leave a tail on the last sample, which the conversion tool might recognize as further bytes. These bytes can be removed in a hex editor to create a clean dump.
5. The current rom is hardcoded to dump 1mb.
This is not meant to help illegal rom spreading.