01-13-2020, 10:45 PM
I have a drive that the SCP app reports as reading 42 tracks (or more iirc), and does seem to step that far. Some random information I found on a random forum said this drive is a 96tpi model so that's the DriveType I've been using. Nearly all the images it creates in both Index and Splice mode load fine in HxCFloppyEmulator and I can use the "Disk Browser" to see the files and have exported some. (I have not verified whether absolutely all content is there but it sure seems to be.)
That said, whenever I open "Track Analyzer" in HxC the disk shows up with 20 rings of data around the outside followed by some 20 rings of noise in the middle. During another experiment I set my DriveType to 48tpi, and two magical things happened:
1. A "bad disk" ended up being readable by HxC, still a few "sore" (red) spots in its MFM decode but browseable!
2. Despite still setting it to scan 42 tracks, the "hole" of noise went away and HxC is showing sectors all the way to the middle!
So now I'm really confused. What does the DriveType (tpi) setting do? I thought the floppy hardware interface just took in pulses and stepped the head motor one step per pulse. So if SCP is pulsing 42 times as it reads the disk what does it matter how many "inches" that would be? I should also note I do have "Half-tracks" selected but half the time it ends up greying itself out and I don't know when/if that has any effect either.
What are the implications of imaging ~forty disks with the DriveType set to 96tpi if it appears that 48tpi gives better results? Are my existing dumps actually corrupted on half the data, just not a half with the FAT directory entries?
That said, whenever I open "Track Analyzer" in HxC the disk shows up with 20 rings of data around the outside followed by some 20 rings of noise in the middle. During another experiment I set my DriveType to 48tpi, and two magical things happened:
1. A "bad disk" ended up being readable by HxC, still a few "sore" (red) spots in its MFM decode but browseable!
2. Despite still setting it to scan 42 tracks, the "hole" of noise went away and HxC is showing sectors all the way to the middle!
So now I'm really confused. What does the DriveType (tpi) setting do? I thought the floppy hardware interface just took in pulses and stepped the head motor one step per pulse. So if SCP is pulsing 42 times as it reads the disk what does it matter how many "inches" that would be? I should also note I do have "Half-tracks" selected but half the time it ends up greying itself out and I don't know when/if that has any effect either.
What are the implications of imaging ~forty disks with the DriveType set to 96tpi if it appears that 48tpi gives better results? Are my existing dumps actually corrupted on half the data, just not a half with the FAT directory entries?