Input Control Lines; Reduced Write Current - Tandon TM602S Operating And Service Manual

3.2 INPUT CONTROL LINES
There are two kinds of Input Control lines, those that are
multiplexed in a multiple drive system and those that do the
multiplexing.
The Input Control lines that are mUltiplexed include:
1. Reduced Write Current
2. Write Gate
3. Head Select
4. Step Interface
5. Direction In
The Input Control lines that do the multiplexing are:
1. Drive Select 0
2. Drive Select 1
3. Drive Select 2
4. Drive Select 3
3.2.1
Reduced write Current
When this Input Control line is activated low'(true) in
conjunction with the write gate, a lower value of write
current is selected for writing on the disk. When the signal
is set high (false), the higher value write current is
selected. When writing on Tracks 0 through 127, it is
recommended that this line be set false. For Tracks 128 and
greater, the Reduced Write Current line should be set true.
A 220/230 ohm resistor pack allows the line to be terminated.
3.2.2 Write Gate
The Write Gate signal enables data to be written on the disk
when it is activated or when the logical zero (true) level is
reached. The ready line must be valid before write gate is
activated. If a disk drive fault occurs, further writing on
the disk is propibited. In addition, the Seek Complete line
should go true before you begin to write any information on
the disk.
The
line
inactive or logical high (false) level on the Write Gate
enables the step pulses to step the head, arm actuator.
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