Jump to content

Net MD Transfer rate

Rate this topic


SileEeles

Recommended Posts

This was just something I noticed during various messings about and I thought it was worth sharing. I have no idea if it has been mentioned before.

It concerns the transfer rates of NetMD. I don't know if minidisc.org is the most up to date with its information but it states:

"SP mode audio at 1.6x is 2.25Mbps (i.e. 1411.2kbps*1.6)"

However, I think this is incorrect. It does also go on to say "perhaps driver or interface problems that restrict NetMD USB transfers to roughly 2.5Mbps really are limiting the speed of SP mode transfers" and says that USB 2.0 could help but so would fixing whatever the USB 1.1 problem is.

I couldn't tell you if this has been fixed, but just from what I've noticed, I don't think the 1.6x is right.

When you cue a song to play at 1.6x and start it at the same time as an SP NetMD transfer begins, the transfer is over well before the song is.

I also noticed that SonicStage transfers finish at 95%. Once there, it will do one of two things:

If you are transferring using battery power, it will stop and write TOC information before continuing with the next song. You can hear this happening on the device itself, since the whole laser/recording aperture is quite audible when going back and forth.

If you are transferring with the power supply, it will simply finish at 95% and then continue with the next song. The TOC information is written after everything else is finished. Again the noise from the device confirms this, the laser isn't going back and forth between songs, it is just a continuous process until the end.

So with that in mind, I figured I would speed up the music a tad to. 2.0x. I started the music at the same time as the transfer started and it was certainly a lot closer, but the music finished a tiny bit ahead of the transfer, so I slowed the music down to 1.9x. Both finished at exactly the same time, and this was tested a few times with a few different songs of varying length.

Which leads me to a few possibilities. The problem that was mentioned by minidisc.org (being restricted to a certain bandwidth) has been fixed, or the use of USB 2.0 actually helps. But then I could still be wrong, since I use a 64-bit driver. I don't know how much it differs over the 32-bit one that comes with SonicStage.

Anywho, just thought they were observations worth sharing.

  • Like 1
Link to comment
Share on other sites

95% is definitely the moment at which it writes the TOC. 30% is the moment when it finishes setting up (I suspect massaging the source data but not sure, you can test on very long track transfers TO NetMD which I never do, preferring HiMD for opera when I am putting onto a disk for listening).

In my experience the best way to get a song with dropouts (even on the MZ-N910, one of the later NetMD units) is to try doing it without being plugged into the charger. Why? Because most of them do NOT pass power to the device. The simple test is to see if the act of plugging in the USB will charge and/or activate-the-recorder-when-there's-no-battery.

All HiMD units will charge from USB (and so do not suffer from this difficulty).

If you switch to the last drivers (the ones for the RH1, NETMD052.SYS and NETMD760.SYS for 32-bit and 64-bit respectively) I have a hunch that the timing constraints go away. However without the use of the reconfigured INF file (for 32 bits) that I supplied, you will get one of the old drivers intended for the earlier models. These are the drivers known to cause upload problems with the RH1, once installed, and I would guess it has some effect on PC->MD data traffic too.

If you are already using the RH1 drivers.......? - then my comments are probably a bit random.

HTH.

Link to comment
Share on other sites

95% is definitely the moment at which it writes the TOC. 30% is the moment when it finishes setting up (I suspect massaging the source data but not sure, you can test on very long track transfers TO NetMD which I never do, preferring HiMD for opera when I am putting onto a disk for listening).

In my experience the best way to get a song with dropouts (even on the MZ-N910, one of the later NetMD units) is to try doing it without being plugged into the charger. Why? Because most of them do NOT pass power to the device. The simple test is to see if the act of plugging in the USB will charge and/or activate-the-recorder-when-there's-no-battery.

All HiMD units will charge from USB (and so do not suffer from this difficulty).

If you switch to the last drivers (the ones for the RH1, NETMD052.SYS and NETMD760.SYS for 32-bit and 64-bit respectively) I have a hunch that the timing constraints go away. However without the use of the reconfigured INF file (for 32 bits) that I supplied, you will get one of the old drivers intended for the earlier models. These are the drivers known to cause upload problems with the RH1, once installed, and I would guess it has some effect on PC->MD data traffic too.

If you are already using the RH1 drivers.......? - then my comments are probably a bit random.

HTH.

My thoughts were since the 64-bit driver I was using was newer (I think the one you supplied) then this might have something to do with the faster transfer, but without knowing what the speeds would be on a USB 1.1 connection or with the 32-bit drivers, I don't really have anything to compare to.

The device tested was my N710 which requires the battery, the USB alone does nothing, and the same goes for my N510.

I am slowly starting to move away from NetMD in certain instances, certainly where gapless playback is required, but I have no issue with it. SP (which is not actually SP from what I understand) and/or LP2 still sound fine to me. LP4 is where I start to notice various audio artifacts and things that sound "watery" to me, so I don't use that.

Link to comment
Share on other sites

Ok if you are only using the 64-bitter then there's no (new) information you can generate.

The older drivers definitely had weird polling loops and such to cope with 1.1USB but I think the new driver does work in all cases, at least no one has reported issues.

My concern was lest you were actually using one of the (old) 32 bit drivers by accident. But that doesn't seem likely, from what you are telling me

Cheers

Stephen

Link to comment
Share on other sites

If you are transferring using battery power, it will stop and write TOC information before continuing with the next song. You can hear this happening on the device itself, since the whole laser/recording aperture is quite audible when going back and forth.

If you are transferring with the power supply, it will simply finish at 95% and then continue with the next song. The TOC information is written after everything else is finished. Again the noise from the device confirms this, the laser isn't going back and forth between songs, it is just a continuous process until the end.

Just an observation - the MZ-N1 does not behave this way. It writes to TOC after every NetMD track is transferred, even when transferring many tracks at once. I know because I used my NZ-N1 for the very first time last evening to transfer tracks to disk via NetMD (SimpleBurner) and the MZ-N1 was plugged into the wall's power outlet. At the time I thought the TOC writing behaviour was strange, because I hadn't remembered my MZ-N505 (the portable I normally use for NetMD transfers) ever writing to TOC after each track (as you say, the NZ-N505 seems to write to TOC once after all the tracks are finished transferring).

Or at least that's what I can tell. The MZ-N505's screen doesn't tell you much during transfer other than "PC-->MD". On the other hand, the MZ-N1's screen is much more helpful. There is a red LED that flashes during data transfers, and the screen actually shows how much of the track has been transferred in minutes and seconds DURING the transfer. It then also shows "TOC EDIT" or "SAVING" or something similar after each track is transferred. It's a nice portable. If it didn't suffer from the weak overwrite head ribbon cable it would be perfect.

Perhaps the MZ-N1 is different, though, because it was the very first NetMD portable. Maybe Sony streamlined things afterward.

Link to comment
Share on other sites

Just an observation - the MZ-N1 does not behave this way. It writes to TOC after every NetMD track is transferred, even when transferring many tracks at once. I know because I used my NZ-N1 for the very first time last evening to transfer tracks to disk via NetMD (SimpleBurner) and the MZ-N1 was plugged into the wall's power outlet. At the time I thought the TOC writing behaviour was strange, because I hadn't remembered my MZ-N505 (the portable I normally use for NetMD transfers) ever writing to TOC after each track (as you say, the NZ-N505 seems to write to TOC once after all the tracks are finished transferring).

Or at least that's what I can tell. The MZ-N505's screen doesn't tell you much during transfer other than "PC-->MD". On the other hand, the MZ-N1's screen is much more helpful. There is a red LED that flashes during data transfers, and the screen actually shows how much of the track has been transferred in minutes and seconds DURING the transfer. It then also shows "TOC EDIT" or "SAVING" or something similar after each track is transferred. It's a nice portable. If it didn't suffer from the weak overwrite head ribbon cable it would be perfect.

Perhaps the MZ-N1 is different, though, because it was the very first NetMD portable. Maybe Sony streamlined things afterward.

See, for someone like me, the information that you say the MZ-N1 gives you during transfer would be very interesting to me. Of the both of my devices, neither of them give much information other than "PC->->MD" and whilst a track is actually transferring the display doesn't really do much of anything, or at least anything interesting.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...