> Date: Fri, 20 Apr 2001 19:16:08 -0700 (PDT)
> From: jsquishee <[EMAIL PROTECTED]>

> Yes, subject says most. I am most interested in this one topic.
>
> >From what I have read in various discussions (over the web and through
> the computer...) on many websites, people have fought over the
> posibility of recording data on a MD portable. While nearly
> impossible, if one was to bypass the ATRAC CODEC, it could be done*!
>
> But that is not what I am focusing on. I have a Sony MDH-10 drive(MD
> Data, MD audio play only). I would like to drag and drop MD tracks to
> it, but, several things limit that ability.
>
> One, the nature of the structure of the disc, the TOC. Every time the
> audio data is changed (lenghtened, split, title, track number,
> etc...), the TOC must be updated to accomidate this change. Therefore,
> software would need to be made which updates the TOC when a change was
> made on the audio portion of a MD. In accordance, any transfer of
> tracks would have to be orchestrated by a program.
>
> Two, something inhibits the drive from recognizing the audio disc as
> readable (directly from the drive icon). It is known that this lies in
> the firmware of the drive. This needs to be hacked.
>
> Three, ignoring MDLP(ATRAC3), an ATRAC1 coder would have to be written
> to convert .wav, mp3 files, etc... to ATRAC1 format. Since ATRAC3 is
> already part of some encoding software (and is available for
> download), it would be the first target(being the easiest to
> implement).
>
> Lastly, some type of distribution service could be devised, at a later
> date, if this indeed comes to fruition.
>
> If anyone is interested, please contact me, as I need all the help I
> can get!
>
> Thanks,
>
> John Pariseau
>
> *But not as easy as I state it.

This is a subject very near and dear to my heart. I have already done quite
a bit of research on the topic. I am continuing to research the topic.
You'll note that I've scanned the MDH-10 service manual and it's now online
on www.minidisc.org; this will give you plenty of information to assist in
the goal.

re: Drag and Drop: all you need is to write a filesystem driver for your
favorite operating system. The MiniDisc TOC is a pretty simple structure, no
problem at all to manage that. The harder part is getting through the
firmware to actually get audio data. Writing a filesystem driver for Linux
is pretty straightforward. Writing for Windows is more of a pain, because
Microsoft hasn't really documented the APIs very well, and they change from
version to version. You could also forego the filesystem driver, and just
write an Explorer-style program, which would at least allow you desktop
drag&drop access. Not the most convenient in the long run, but a start.

re: ATRAC1, ATRAC3: ATRAC3 is already a done deal. You can download a codec
from www.minidisc.org and use it to your heart's content. Much of the code
can be re-used for ATRAC1: the input and output filters, the MDCT code, and
the transient/spike detection logic. Of course the filtering and MDCT
behavior are not identical for ATRAC1, but close enough to modify to fit.
Getting the actual on-disk data structures decoded correctly might be a
challenge.

I've recently obtained a Sony MDM-X4 (4 track recorder) to accompany my
MDH-10. It records on MD-Data discs, but so far the format has been
unreadable on my MDH-10. The MDH-10 is smart enough to know that MD-Audio
discs use 2336 byte blocks, and regular MD-Data discs use 2048 byte blocks.
Unfortunately, MD-Data discs used in pro recorders actually use 2332 byte
blocks, and I haven't found the proper command yet to reset the block size
to get it to read...

By the way, what firmware version is on your MDH-10? I have 1.11, which is
missing several SCSI commands that I thought it should have. I have an old
email from Eric Woudenberg listing about 40 supported SCSI commands,
including Read Buffer, various mode support, etc., but Read Buffer isn't
supported on my drive. From the Sony web site, I see that 1.19 is the
latest. I'm going to look into ordering a firmware update from Sony...

  -- Howard Chu
  Chief Architect, Symas Corp.       Director, Highland Sun
  http://www.symas.com               http://highlandsun.com/hyc

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