Can anyone explain what exactly does that IC memory do on those really expensive Sony MiniDV tapes? Is that just a gimmick, or is it worth the expense?

There's my post! Thanks for moving it to a more prominent spot Jeff.

Anyone know the deal-io?

You do not need it. It stores certain information about the recording on the tape and most home and prosumer camcorders cannot use it.

What information does it record? Anyone know what cameras can use the feature and what the details are on what it records?

As I understand it, the chip is useful if you use the Sony editing system. You can log takes on it, so the system will, allegedly, automatically capture the correct takes. I don't know anybody who's ever used the tape...well, I did one time when we bought some by accident.

I just found this tidbit on a site... Not too specific, but here it is:\

What is the Memory Chip (IC Memory) for.
The camera manufacturers can set up their cameras to record virtually anything on this chip including a titles, recording times and dates, and camera settings used. You should check your camera user manual to see if your camera can make use the chip and what information would be stored.

And then I found this about the Sony VX2000:

"I've seen lots of concern about writing continuous time code to tape when you need to change tapes in mid-stream - a non-problem for the VX2000 - if you use tapes with IC memory. You simply tap the "end search" button and the camera automatically searches for the end of the last recorded segment, ensuring unbroken time code. "
- http://www.videouniversity.com/vx2000.htm

That's interesting, I use the end search button all the time on a DSR250 and don't use the IC tapes.

I have used Sony tapes w/chip on Sony PD150, Sony PC100 and a whole load more of Sony model variations. The chip doesnt do much use unless you swap tapes. Any camera can use end-search if it has that function and will always find the end of your last recording, as long as you dont mess up timecode, or time on non-timecode cam, so you always get the end. However with non-chip tapes, as soon as you eject the tape, the camera cannot remember or find the end using end-search. But with the chip tape you can always find the end. I dont really use the chip tapes as i normally fill one tape, before moving onto another. But they are handy for me when i use them as "test" tapes or when I use a tape for just little things like recording title sequences or short films, then I can always find the end, even after removing the tape numerous times. They were handy at uni when you had to use shared cameras at scattered times, and always checking tapes so never in the same place twice.

So even if your not using a VX2000 the chips still work on other Sony cams, not sure about other ones though, but its up to you if the added cost for 4k chip is worth it or what your video situation dictates.

That's interesting, I use the end search button all the time on a DSR250 and don't use the IC tapes.

Sony machines can do an end search on IC-less tapes as long as they are not removed from the camera. If you take the tape out, and then replace it, the camera will lose the end.

Tapes with ICs, though, can be removed and reinserted without losing the end point -- it's recorded on the IC.

If you want to maintain continuous time codes, all you need do is back the up to the last valid time code. The system will then resume the time code from that point.

It is also important to use good shooting technique. You should be doing both a pre and post roll. This makes editing much easier.

I'm glad you brought that up. The thing that drives an editor to drink is broken time codes. All you have to do is shoot a few seconds of rundown at the tail of your shot and a few seconds of rundown at the head of the next shot, which is what you should be doing anyway regardless of time code. As one of the above posts mentioned, if you take a tape out of the camera, unless it's an IC tape, you may have to reset the time code when you put it back in.

There's one more way to screw up the time code, and that's when changing batteries. With my old BVW300 this never happened, but with the DSR500, it does. I power down, remove the battery, replace it...the time code is continuous on the counter and all is well...NOT. What you have to do is hit the auto replay button the lens, which will back the tape up a few seconds and play it to the end of the shot, and all will then be well. If I don't do that, there is a black hole in the tape. When batch capturing the footage, the Avid goes nuts trying to jump across that gap...even if the record-across-time-code-breaks button is checked.

Keeping your time code straight is easy, but people sometimes neglect the basics when they get in a hurry. Remember that **** rolls downhill, and anytime you cut corners during the shoot, you will pay for it later.

The reason I know all this stuff, by the way, is not that I'm blessed with intelligence--rather, I'm blessed with longevity. If there's a mistake out there, I've already made it.

The main intention (other than making more money on them) is the ability to edit in camera with these tapes. They allow titleing in camera and a few other extras but personally they are not worth the added expense.Lets face it , most folks edit on there computers and so have no need of these tapes.
Maybe they are more popular in Japan like all the special , in camera, effects.