Too bad because I have a feeling that if that were working it would be a lot more reliable.]]>I want to follow Oliver's instructions on this type of backup and make audio storage from my banks. But I think I'm too dummy for the 2.3 manual, because I just can't get it to work. I go to the bank number in the top right of the screen, then press A + B + up, to copy bank to buffer. Then A + B + down, to receive bank to buffer. And then A + B + up to encode bank as audio pulses. But when I start the audio playback with the B button, nothing happens.
Anybody knows what I'm doing wrong?
]]> Too bad because I have a feeling that if that were working it would be a lot more reliable.]]>y0 oliver! Is there a program to convert recorded files to binary files, or do you rely solely on the method of using audio out for restoring data? I'd like to try making two things.
1) A program that analyzes these audio files and extracts the binary data.
2) A program that sends data back to the cartridge. This could be done using an Arduino or with program that runs on a second Gameboy and acts as a data storage. One doesn't exclude the other, of course.
A program running on a second Gameboy could obviously also act as a receiver and backup storage. (Assuming NL can also send data through the serial port.) This would also go well with my LittleFM project.
The problem for me though, is that I don't have a Nanoloop cartridge. I'm not going to beg for free a NL cart (although I wouldn't say no to one 
) but Oliver, could you please provide me with a binary save file (for reference) and an audio recording of the same file?
Also, does the transmitted data come with a checksum of some sort?
Oliver, if you want, you can reply to [my username]@gmail.com
]]>"I'm sorry for how little development / information there was with the audio/data backup yet.
While I was looking for a simple backup solution that would be cheap / easy to DIY, I came up with the idea to record / play back the data as audio (inspired by the datasette: http://en.wikipedia.org/wiki/Datasette). The link port protocol is slow and robust enough and there is one line for clock and one for data, so I gave it a try. While recording the data didn't work well, it was actually possible to send bytes by playing specially prepared audio files on a PC. In nanoloop 1.5, I implemented a function that encodes a bank's data in this form. So it is possible to archive the data on a PC in form of a recording. It is also possible to restore that bank on a nanoloop 1.5 cart by simply connecting the PC's audio out to the Game Boy's link port and playing back the recording.
However, I soon found that it only worked on my MacBook and only at maximum volume, I could not get it to work on any other computer yet. It seems to be an issue not just of voltage but also resistance or capacitance. It often seems to work, but then data suddenly get scrambled, it's like the voltage is drifting. I have tried a number of ways to stabilize the signal and adjust the offset (comparator, optocoupler) but with no luck yet.
The problem is that audio line-out operates at a much lower voltage than the game boy's 5V, that it's positive and negative (-2V to +2V) and that the signal is pulled to ground.
I'm not familiar with audio electronics, I just know they're rather different from (CMOS) logic and both probably shouldn't be coupled directly. But I'm still optimistic that a very simple circuit can solve the issue and make it work for any device with a line-out.
The connections are as follows:
left - clock
right - data
ground - ground"
http://www.nanoloop.com/node/1069
Fingers crossed.
]]>I emailed Oliver Wittchow inquiring about the cable and whether schematics are available, so I'll see what he says.
did yew ever hear back from him?
or try and post this inquiry on the NL forums?
a simple answer might save a lot of time + effort.
]]>Interesting. Will voltage not play a role in this? It would change based on the playback volume... unless its only looking at zero crossings I guess.
Depends on how complex the analysis is on the coding side. It could use the clock sound as a way of calibrating it since that has a constant amplitude.
]]>The data is in stereo. It looks like the left audio may be a clock while right audio is sending the data.
Here you can hear/download an audio file creating with a NL1.5 data backup:
Open this file in audacity if you want to analyze it. Please post here or PM me if you have any ideas beyond my basic ones.
This weekend I'll attempt to load it back onto the cart by splicing the audio cable with a ink cable and trying different combinations of connections. I feel it may be as simple as that, but only time will tell.
If I have any success I'll obviously post the schematics here.
]]>as far as i know this is still vaporware.
i would guess it's just a standard 1/8" cable, and a piece of software to decode/encode
whatever is coming out of the gameboy. but since i havnt seen any for sale, or even in use,
i cant say for sure... i would post on the NL forums and it a direct answer from oliver.and as a note. (it's in the manual)
since NL uses a non-standard memory setup, normal GB backup devices will not work,
and actually might mess your cart up (during the checking phase). so dont try and
backup NL w/ a mega memory cart.
We know that it's vaporware, we're now trying to figure out how to build our own. Based on the descriptions we've heard the audio that is output is not processed on the receiving end (it is, in fact, just recorded as regular audio), but rather when it is returned via the link port. If that's the case, we simply need to figure out how to build that cable and we won't need any deep understanding of encoding/decoding process.
I just got my Nanoloop 1.5 cart back from a friend who was borrowing it and I'm going to make a recording of the encoded audio to do a little analysis. I really just want to see if there's stereo audio and if there is a relatively obvious clock signal on one of those channels. Once that's done it's as simple as splicing a cable and seeing which link cable pins are used as the inputs.
]]>i would guess it's just a standard 1/8" cable, and a piece of software to decode/encode
whatever is coming out of the gameboy. but since i havnt seen any for sale, or even in use,
i cant say for sure... i would post on the NL forums and it a direct answer from oliver.
and as a note. (it's in the manual)
since NL uses a non-standard memory setup, normal GB backup devices will not work,
and actually might mess your cart up (during the checking phase). so dont try and
backup NL w/ a mega memory cart.