This info about the different BKDSK extensions (courtesty of peter_j himself) is worth reposting so we don't forget:
viewtopic.php?p=13797#p13797The answer was right there!
Quote:
First byte of file is media type.
01h: 2HD-8 sector (1.25MB) (BKDSK .HDM) (aka 2HS)
2 sides, 77 tracks, 8 sectors/track, 1024 bytes/sector = 1261568 bytes (360rpm)
02H: 2HD-15 sector (1.21MB) (BKDSK .HD5) (aka 2HC)
2 sides, 80 tracks, 15 sectors/track, 512 bytes/sector = 1228800 bytes (360rpm)
03H: 2HQ-18 sector (1.44MB) (BKDSK .HD4) (aka 2HDE)
2 sides, 80 tracks, 18 sectors/track, 512 bytes/sector = 1474560 bytes (300rpm)
04H: 2DD-8 sector (640KB) (BKDSK .DD6)
2 sides, 80 tracks, 8 sectors/track, 512 bytes/sector = 655360 bytes (300rpm)
05h: 2DD-9 sector ( 720KB) (BKDSK .DD9)
2 sides, 80 tracks, 9 sectors/track, 512 bytes/sector = 737280 bytes (300rpm)
08h: 2HD-9 sector (1.44MB)
2 sides, 80 tracks, 9 sectors/track, 1024 bytes/sector = 1474560 bytes (300rpm)(??)
11h: BASIC-2HD (BKDSK .HDB)
See HDB description.
19h: BASIC 2DD (BKDSK .DDB)
2 sides, 80 tracks, 16 sectors/track, 256 bytes/sector = 655360 bytes (300rpm)
21H: 2HD-26 sector
2 sides, 80 tracks, 26 sectors/track, 256 bytes/sector = 1064960 bytes (??rpm)(??)
Incidentally, the .ddb file will work in np2fmgen without conversion. Just manually set the file open filter to all files (*.*).
By the way, does anybody have a copy of the actual BKDSK program? I can't seem to find it.