11-14-2016, 01:34 PM
As stated in the SDK, the after a step command is issued, there is a delay (5ms default). After a seek to track 0 command is issued, there is a delay (15ms default). These are guaranteed by the hardware. The SCP software sets these to 20ms and 50ms respectively, which is overklll.
The 300/360 RPM flags are only used when ff_Index is not used. The 300/360 flag is then used as a timeout for the reading (or writing) of either 200ms or 166.667ms.
Every drive is different. Some drives CAN be controlled by the density select to change the drive speed, but most 3.5" disk drives do this automatically using the HD hole sensor. When a high density (1.44MB) disk is inserted, typically the drive goes to 360 RPMs and when a low density (720K) disk is inserted, typically the drive goes to 300RPMs. However, this brand dependant which can be changed by jumpers.
The 300/360 RPM flags are only used when ff_Index is not used. The 300/360 flag is then used as a timeout for the reading (or writing) of either 200ms or 166.667ms.
Every drive is different. Some drives CAN be controlled by the density select to change the drive speed, but most 3.5" disk drives do this automatically using the HD hole sensor. When a high density (1.44MB) disk is inserted, typically the drive goes to 360 RPMs and when a low density (720K) disk is inserted, typically the drive goes to 300RPMs. However, this brand dependant which can be changed by jumpers.