Mfm Read Data; Data Line Driver/Receiver Circuit - Tandon TM602S Operating And Service Manual

HIGH
- - - - - - I
TRUE
26LS31 OR
EQUIVALENT
20 FT
~1IIIIllII
MAXIMUM
~
I
(6.1 MI
~
I
FLAT RIBBON OR
I
i
TWISTED PAIR CABLE
+
SIGNAL
- SIGNAL
Figure 9
26LS32 OR
EQUIVALENT
HIGH
> - - -
TRUE
Data Line Driver/Receiver Circuit
Write Data line goes more positive than the minus (-) MFM
Write Data line, provided that the Write Data line is
~ogically low (true). When the disk drive is in a R~ad mode,
the host system must ensure that the MFM write data signals
are in the inactive state. The inactive state can
be
attained by making the plus MFM Write Data line more
negative than the minus MFM Write Data line.
3.4.2
MFM Read Data
These lines are a differential pair that recover the data
previously written on a track. A flux reversal on the track
to be read is caused When the plus MFM Read Data line goes
more positive than the minus MFM Read Data line. Subse-
quently, the differential pair signal is transmitted to the
host system via the MFM Read Data lines.
3-7