The standard command set of 1050 (810) drives:
$52 R Read sector
$50 P Write sector
$57 W Write sector with verify
$53 S get controller status, returns 4 bytes
byte 0 drive status
bit 0 – Command frame error
bit 1 – Checksum error
bit 2 – Operation error
bit 3 – Write protect
bit 4 – Motor on
bit 5 – double density
bit 6 – unused
bit 7 – Dual (medium) density
byte 1 controller status, returned values are inverted
bit 0 – busy
bit 1 – drq
bit 2 – lost data
bit 3 – crc error
bit 4 – record not found
bit 5 – record type
bit 6 – write protect
bit 7 – not ready
byte 2 time-out (format); $e0
byte 3 unused; always 0
$21 ! format disk (single for 810 and stock 1050) as defined by CMD $4f for upgraded 1050 and XF 551
(heard, that they will give back 128/256 bytes?)
$22 “ format enhanced (medium, dual) density (1050)
Special 1050 diagnostic commands:
$23 special diagnostic command, must be followed by CMD $24 first byte is the command
$00 RPM-measurement
$01 motor speed-up time
$02 step-rate
$03 do half-steps
$04 write-test
$05 seek on track
$24 get results of $23 CMD
These are supported by all double density drives:
$4e N read drive configuration; returns 12 bytes
byte 0 number of tracks [1 for harddisks)
byte 1 step rate
byte 2 sectors/track high (total number for harddisks)
byte 3 sectors/track low
byte 4 number of heads decreased by one
byte 5 format (0=FM; 4=MFM)
byte 6 bytes/sector high
byte 7 bytes/sector low
byte 8 drive activated
byte 9 unused
byte 10 unused
byte 11 unused
$4f O write drive configuration; see above
$3f ? get high-speed-index Happy,
US-Doubler, HDI (Germany) return $0a Speedy (Germany) returns $09