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I have a BTC 52/24/52 drive in an external USB 2.0 compatible enclosure. This drive has a coaster protection feature called Super Link. I burned several CDs with this drive plugged into an older computer with only USB 1.1 ports. Consequently, the interface couldn't keep up with the burn and you could see the buffer underrunning and Super Link activating numerous times for each burn. I was using Nero Express 5.5.9.16 for the burn at 20X.

Now the discs burned are all perfectly readable in the external BTC drive which burned them, but come up with CRC read errors when I try them in any other drive I have (a Ricoh 5125a DVD burner and an Asus E616 DVD-ROM). I tried limiting read speed with Nero DriveSpeed, but it didn't seem to help. Does anyone have any suggestions? And has anyone come across a similar problem before? The discs are an assortment of different brand discs, but mostly CMC Magnetics ones. I should note that when plugged into a computer with fullspeed USB 2.0 ports, the discs produced with this external BTC CDRW are fully readable by any optical drive.

I would try burning the dics at a maximum speed of 6x since usb1.1 can't handle the 20x burn speed you were using.

What brand of discs are you using, and do you have the latest firmware on the drive?

David has the right idea here. If you're trying to write at anything faster than 6x with USB 1.1, the recording process is going to stop and start every few seconds. While SuperLink will let you complete the process, the gaps it creates from starting and stopping will make the disc hard to read.

Ian wrote:David has the right idea here. If you're trying to write at anything faster than 6x with USB 1.1, the recording process is going to stop and start every few seconds. While SuperLink will let you complete the process, the gaps it creates from starting and stopping will make the disc hard to read.

i still find this answer unacceptable.

what's the point of Buffer-Underrun-Protection/Prevention-Technology if not to allow us to burn a CD with buffer underruns (edit: i should say with "potential buffer underruns", or more precisely "would-have-been buffer underruns that were prevented thanks to this technology") and still have a functional disc rather than a coaster?
if it works, it should work. and if it doesn't well then what's the point of having this technology at all?

OK it creates gaps, the idea is that the disc should be readable despite these gaps.

I have to agree with Dodecahedron because I have seen a drive use it's buffer-underrun prevention technology a large number of times on a single burn (because DMA was off), and the disc was still perfectly readable.

CDRecorder wrote:I have to agree with Dodecahedron because I have seen a drive use it's buffer-underrun prevention technology a large number of times on a single burn (because DMA was off), and the disc was still perfectly readable.

Buffer underrun technology was designed with the occational buffer underrun error in mind. Not a continous stream of them. Remember that the starting and stopping creates a small gap in the data. While a small gap here and there probably won't phase a drive's error correction, millions of errors might cause problems with some.

Think of it this way. When you're driving your car you might not feel one small pot hole on the road. But imagine if that road is filled with many small potholes. Even with your car's suspension, you're definitely going to feel that.

Okay, most of the discs are 40x rated "Fashion Master" brand - I got them cheap in bulk, from a seller off an online auction site. They are CMC Magnetics discs and are reasonable discs I think - I've used a lot of them for a while.

Anyway, to the point I have 56 discs mostly of this type burned in the method I was describing, i.e. at highspeed (20x) hooked up to a USB 1.1 port, and buffer underrun prevention activated numerous times for each burn. I thought it was okay, because that is what buffer underrun technology is for right? Plus verify was turned on, and each disk verified fine, so I thought this was cool too. Anyway, these disks are not readable in most of the drives I have tried them in. Short of reburning them, is there anything I can do to make them readable with some software tweak? Are there drives which read superlinked disks better than others?

I doubt that there is anything you can do other than reburning the discs to make them readable by other drives. It would probably help if you burned your discs at 4x when using a USB 1.1 port.

hey, at least SOMETHING you have can read them

Ian wrote:Buffer underrun technology was designed with the occational buffer underrun error in mind. Not a continous stream of them. Remember that the starting and stopping creates a small gap in the data. While a small gap here and there probably won't phase a drive's error correction, millions of errors might cause problems with some.

Think of it this way. When you're driving your car you might not feel one small pot hole on the road. But imagine if that road is filled with many small potholes. Even with your car's suspension, you're definitely going to feel that.

Good comparison, Ian.

I just scanned my disc which had experienced many pauses due to buffer-underrun in KProbe, and I got a normal result for the type of media I was using. The disc was burned in a Philips PCRW1208 with Seamless Link. I wonder if the SuperLink on Robotnik's drive doesn't do as good of a job as other types buffer-underrun protection.

I don't think your problem can be totally blamed on SuperLink, per se. There are too many issues involved, and blaming the symptoms on SuperLink is an oversimplification. I haven't seen a documented case yet where buffer underrun protection use was proven to cause an unreadable disc.

It is more likely that:

1. The CMC discs you are using are not of the best quality and may contain CRC errors.

2. CRC errors, if present, are not being picked up when the discs are read with a USB device.

Try reading the discs with the DVD-ROM and/or DVD burner with DMA temporarily disabled for those devices. Reboot before reading with the drives. The drives will revert to PIO mode, which does not do CRC error checking. This procedure may allow you to read the discs without error messages in other drives.

You should alway burn at the correct burning speed for the transfer protocol with good quality media. Read the first page of Media Compatibility With CD-RW Drives - Which Media Is Best? to get some reports of media performance.