mikey@trsvax (07/17/85)
You CAN read 96 TPI disk on a 48 TPI drive. Tandy and IBM do it all the time. The problem is that the 96 TPI drives lay down a much NARROWer track. If you write on a diskette that was originally done 48 TPI with a 96 TPI drive, there might be garbage on either side of the true signal. Reading back on a 96 TPI drive is no problem, because it also reads a narrower track. But put the same diskette back in a 48 TPI drive and the wider head will read a wider track, including trash from before the 96 TPI track was laid down. Personally, I've never had more than a minor problem with this, I just retry and it will always get the info, but it is possible that you might never get it. The safeest way is to use a BULK ERASED diskette if you are going to format it as 48 TPI on a 96 TPI by double stepping. Then the data you write on the diskette with the 96 TPI drive will have a nice "quiet" background on adjacent tracks. From person experience, it seems that this is most critical durring format and actualy data laid down is much more lenient. It probably has to do with the sector header info, I've never really looked into it, why question with success? mikey at trsvax Please take everything here as my personal opinion as it has no official standing with my employer!