How to restore disks?

Greetings, Oleg! It was 16 Jan 99 and 05:07:00, Oleg Grigoriev wrote to Kirill Frolov on the topic How to restore disks? Not seeing the moderator nearby, I decided to insert a word: OG> No. If the sector is readable, then the header was also readable. OG> tan is true. Maybe, probably... OG> Hands are crooked. OG> ld a,#f0 ;track recording. OG> call topr1f OG> ld hl,buffer ;image address. OG> ld c,#7f OG> ld ix,#3fca ;record. OG> jp to_dos OG> If b at the output =0, then cal. So sometimes something like this doesn’t format and you get a “recording error”. The command #f4 is used. If you shove #d8 in front of it it’s much better, but sometimes still doesn't format. I always wait while other teams are working the 'busy' bit of the status register. Here it looks like INTRQ is required at 1 :-/ And most importantly - after writing the command, I wait until the status register will not be 'busy'. If you don't do this, then nothing will work at all. KF>> there may be several defects on a track. What algorithms are there? OG> Trash can.Masdai. FUT is there too? Think about it: you restored the disk, but it’s RDS. Instead of trying to reformat the road, I ruined your disk. [..about..index..tag..FC..] OG> Hmmm. Why? And HONEY does this and writes 'ERROR!'. I want that too. KF>> What is the _minimum_ track length? OG> Somewhere around 6250. Depends on the disk, and I saw 6220 in my case. the minimum is 6100 or less. I would like to know the permissible deviations in disk rotation speed and frequency quartz in the computer. KF>> Determine the length of the track by KF>> reading from the disk is not possible - when writing, it may turn out to be different due to the difference KF>> in speed for different drives. It is also impossible to calculate the length of the track after KF>> formatting - when writing a sector on another drive, you can get KF>> the sector crawling out of the track. I'm interested in _minimal_ KF>> speed KF>> disk rotation on a _working_ drive. OG> "... The non-contact controlled motor DBU-2 is designed OG> to rotate the disk in the mechanism at speed OG> (300+-4.5) rpm." ~~~~~~~~~~~~~~~~~~~~ ??? Why so little? I have a floppy disk that is difficult to spin and the speed when installed in any drive floats in a very wide range. With best wishes, Kirill Frolov.