Hi Sellam, It means that ANADISK saw gaps in the sector numbering. For example, it might have seen sectors: 1 2 3 4 6 7 8 9 In this case there is a "gap" which is sector #5 missing. Note, it is entirely possible to format a diskette with missing sectors - but most people didn't do it - it most likely indicates that ANADISK failed to read one sector, which is why it reports this as a warning. The higher the track, the smaller the "circle" on the disk with the data, hence the more densly packed the bits are - which can lead to more errors - this is also the area where head alignment etc. can be most critical, and worn drives do tend to give more errors on the inner tracks. But it's may also be a incompatibility between the diskette format and the PC disk controller (I am assuming this is the 8" drive that you have hooked up to a PC). The PC disk controller cannot handle gaps sizes as small as some other systems did - For example, I find that Cromemco disks do not read reliably on my PC. The interesting thing is that certain sectors consistantly do not read on one PC, while DIFFERENT sector(s) may not read reliable on a different PC. When I was working on my replacement for TELEDISK (which I still have not gotten back to), I found that I could sometimes read all the sectors by re-reading the same track multiple times (however at that point you lose the ability to detect the exact interleave), but sometimes even reading the track 50 times would not yield all the sectors. On a different PC, I could read a different set of sectors with about the same reliability. One thing I wanted to add to the program was the ability to merge multiple images read from different PCs into one to "collect" all the sectors. I also found that slowing the drive slightly can make a big improvement on reading some types of disks... (and of course - none of this may actually relate to the problem you are having ... just some of my experiences to help you figure it out) If you format a disk from the PC can you read it back reliably? Regards, Dave -- dave04a (at) Dave Dunfield dunfield (dot) Firmware development services & tools: www.dunfield.com com Collector of vintage computing equipment: http://www.parse.com/~ddunfield/museum/index.html