DOS feature on formatting disk

Hi Gordon There are a number of possibles but the track 0 sensor doesn't effect the incremental stepping mechanism used in these drives. There is no way that it can be off without being completely off and head over the wrong track. One full increment of the step is one track. This is not possible in DOS because it needs to read the headers correctly to write. It is writing so I'd guess it is more likely not a full step issue as would be caused by the track 0 sensor. Anyway, I suspect that by the sound that the unit makes, compared to a good one is that the head assembly is somehow loose or warn. It is not positioning solidly and cross writing the other tracks. All this is academic since getting inside this laptop to the level needed to repair the drive is more than it is worth. This is the unit with the failing video ( one bus bit missing ). Once I get the data off it, I may not do anything else with it. I'm even considering just transferring the hard drive. That is also major surgery on this laptop ( I know because I put an oversized [ byte wise ] drive in there myself ). These things were never intended to be taken apart. I'm mostly pissed because the stupid format command. The drive messes up about every third or fourth transfer. In only about 1/3 of those cases does it trash track 0. I then just use the magnet. Still, I see little reason why it needs to see anything on track 0 if it is doing an unconditional format. You'd think it would just step to track 0 by the sensor and format it. It would then look to see if it was OK. Dwight