From Kent Williams Sent Thu, May 28th 1998, 15:56
From Kent Williams Sent Thu, May 28th 1998, 15:56
On Thu, 28 May 1998, Peter Becker wrote: > Jon, you're kidding right? > Maybe it's true...someone told me the word "gullible" isn't in the dictionary. > > How could this device *work*? I have a sophomore knowledge of electronics > and I could'nt figger this out. > > Date: Wed, 27 May 1998 09:21:26 -0700 (PDT) > > > actually, i just read that someone has developed a big 12" round thing > > that fits on a turntable and sends signals to a specially modified MP3 > > player and can scratch accurately to a millisecond. > Actually Peter, some guy in Europe has done this. I didn't save the article (it went straight to my "eh whatever" bin), but apparently it is something real. He hooks up turntables & mixer to a AtoD convertor, plugs the digital stream into a BeOS computer, which has software that interprets the signal coming off of the vinyl. As for how one might do it, think about how modems work -- frequency shift keying in a limited bandwidth. You can encode position information onto the vinyl record as a modulation of a continuous tone. By figuring out the frequency of the carrier tone, you know how fast the record is spinning. By reading the position code, you know where you are on the record. To handle backspins, you encode the position codes in a frame of unique bit patterns, so you can read and decode a position code forwards or backwards. I've done low level data communications programming so I know this will work, pretty much. Whether it will work if you bump the stylus or get your special records warped and scratch is anyone's guess. For that matter, modems only work most of the time -- they ain't 100%.