MPI 40 Series - Sector; Ready; Read Data; FM Separated Data (Optional Output)

3.5.2.3 Sector
This output line sends SECTOR pulses when a hard sectored
diskette is installed. Normally there are 32 sector holes in
the diskette, so there are 32 negative going pulses each with a
period of 1. 7ms + 0 .3ms. The INDEX pulse is exactly halfway
between SECTOR pulses 31 and O. The leading edge should be used
for reference. See Figure 3-10 for timing.
3.5.2.4 Ready
This output line indicates that the spindle is spinning at more
than 80% of its normal speed, a diskette is in place, and at
present speed at least two INDEX pulses have been sensed. If a
single sided diskette is used READY will be active if side O is
selected, but false if side 1 is selected. There is an option
available which allows double sided diskette to be used in a
single sided drive which is called the "flippy" option.
3.5.2.5 Read Data
This output line provides the raw data (clock and data combined)
as detected by the read/write heads. When the drive is not in a
write mode and all other timing requirements are met, then and
only then will valid READ DATA be sent. See Figure 3-6 for the
timing requirements. For every flux change on the diskette,
READ DATA will send one negative going pulse on this line.
3.5.2.6 FM Separated Data (Optional Output)
This optional output line provides separated data bits from raw
READ DATA in FM encoding only. The drive has an internal FM
data separator. See Figure 3-9 for separated data bit timing.
The FM data separator can provide separate data and clock
information for soft-sectored standard IBM format and address
mark areas.
3.5.2.7 FM Separated Clock (Optional Output)
This optional output line provides a CLOCK separated from FM raw
READ DATA using an internal data separator. Refer to Figure 3-9
for timing.
3.5.2.8 Write Protect
This output line becomes active when a write protected diskette
is installed which indicates that the user should avoid writing
on that diskette. In the standard configuration, when this line
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