Ralf R. wrote:
RWAP wrote:And....making the motor a bit faster (I think there was a potentiometer on the PCB) gives more sectors. So I think, one of your mdv is running a bit faster than the other. I was able to get 235 sectors, but had not used this speed.
This is the opposite of my experience.
During format, he tape loops and sectors are written, counting down from 255 to 0*. At some point, the starting point passes the head and sectors 255, 254, 253... are overwritten by sectors 4, 3, 2, 1, 0. The faster the motor, the more sectors are overwritten. This sets the number of sectors laid out on the cartridge. Then, during a verify process, the highest number sector that hasn't been overwritten is determined, and any detectably bad sectors are omitted.
You would think that arranging it so all 255 sectors are on the microdrive with no overlap, but in my tests I found that the head gap and tape speed sets a limit on data density that is already quite close to the theoretical limit for the media. For basic data integrity, the maximum sensible sector count is about 230-235 sectors. I'm personally much happier with a cartridge that formats to 220-225 sectors.
*practically, not logically