The radio can save different backups to the card, either a full memory
dump (76800 bytes, 0c12c00), only the settings (1024 bytes, 0x400), or
only the memories (25600 bytes, 0x6400).

Filenames and paths, relative to SD card root:

Full memory dump ("clone"): FTM400D/BACKUP/CLONE/CLNFTM400D.dat
Memories (channel data, I presume): FTM400D/BACKUP/MEMORY/MEMFTM400D.dat
Settings: FTM400D/BACKUP/SETUP/SYSFTM400D.dat

The size of the full memory dump minus memories and settings is 50176
bytes, 0xc400, but I guess it is not all empty. I have noticed that
for example incoming APRS messages are stored in memory, but I guess
those would not be saved with settings or memories. Still, having
separate dumps of the settings area and the channel data area should
make it easier to locate those areas in the complete memory dump.

I will have a look at the three files, compare them and verify the
locations in the full memory dump.


A closer look on the Yaesu MH-85A11U shows that it connects with a
(probably modified and non standard) mini USB B only. The female
connector on the radio has the usual five pins of a mini USB B, and
another six pins. Since the DTMF mic that comes with the radio uses
six pins I would guess that those six pins are the same as the regular
mic. If I was developing hardware I would not create new stuff but
rather reuse existing technology, in this case a standard USB webcam
interface combined with the six pin microphone interface already in
use.


I opened the SCU-20 USB data cable, confirmed the presence of a
PL2303. It connects using five leads both to the radio and to the USB,
and I did not at this time remove the shrink tubing to check if the
radio connector cable has all 10 leads or if it is a cheaper five lead
cable. It would probably be quite easy to just remove the PL2303 side
and make a connector for an FTDI interface instead, though. I took
some photos of the inside of the interface cable before putting it
back together.

On Sat, Mar 8, 2014 at 4:54 PM, Johan Adler <johan.adler@gmail.com> wrote:
> Thank you, Tom,
>
> In fact I just made a rough memory map earlier today, just studying the
> memory dump file from the memory card with a hex editor. When comparing my
> guesses with the mapping used by the FTM-350 module most major stuff seems
> to be in the same places. There are new features and settings, of course,
> and I will have to sort those out, but I think I can use the FTM-350 module
> as a starting point.
>
> Of course, one difference is the two different ways of accessing the memory,
> cable or card.
>
> I have not found any way of making the radio save more than one incarnation
> of the memory dump, alas.
>
> One possible interesting (non Chirp related thing) about it is the optional
> camera microphone, which connects (for the camera) to what looks a lot like
> a mini USB B, and where such a cable also fits. What if it would be possible
> to connect some simple webcam instead of the more expensive Yaesu cam mic.
> :-)
>
>
>
>
>

> On Sat, Mar 8, 2014 at 4:41 PM, Tom Hayward <esarfl@gmail.com> wrote:
>>
>> On Sat, Mar 8, 2014 at 12:54 AM, Johan Adler <johan.adler@gmail.com>
>> wrote:
>> > I have cloned the development tree and try to find how the FTM-350
>> > module
>> > works regarding memory download to see if can start there. I can also
>> > start
>> > analyzing the memory image saved to µSD, but it will be a bit tedious to
>> > change one setting, turn the thing off, take the µSD card to the
>> > computer,
>> > copy the settings file, compare it to the previous version, put the card
>> > back, turn on the radio, change another setting, and so on. :-)
>>
>> How many memory images does it allow you to store on the µSD card? You
>> make it sound like just one, unfortunately. If you can store more than
>> one, you could batch a number of changes into respective files before
>> copying to the computer for analysis.
>>
>> Yaesus are pretty simple (actually, most all ham radios are). If you
>> upload the memory image and include a few details like what frequency
>> and PL are in the first three channels, I could probably tell you at
>> least where the channel data starts and how long each record is.
>>
>> Tom KD7LXL
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>
>