Micropolis 1518-Models


Configuration and Jumper Options

Drive Address Selection The Drive Address jumpers are identified as DA1, DA2, and DA3. ID selection is binary, as shown here. The ESDI controller's documentation will specify the drive address to use.
      Drive	  Select Jumpers
     Address	DA3	DA2	DA1

	1	out	out	in
	2	out	in	out
	3	out	in	in
	4	in	out	out
	5	in	out	in
	6	in	in	out
	7 	in	in	in

	"Drive Address 0" (no jumper at DA1, DA2, or DA3) 
	 is a "deselect" (i.e., no drive selected).

For many multiple drive installation, each drive must have a unique address. An exception is that for every drive in a PC/AT installation, verify that the only Drive Address jumper is at DA2; move the jumper if necessary (the special twisted interface cable that is generally used takes care of adding a unique address to each drive). PC/AT controllers can typically support a maximum of two drives. Interface Termination The Interface Terminator factory installed at RN11 provides proper termination for the interfacelines. When daisy-chaining multiple drives, leave the terminator installed only in the last physical drive on the daisy-chain cable; remove the terminator from each of the other drives. In most PC/AT applications, the C: drive is actually at the end of the cable and should retain the terminator
Spindle Control W5 controls the spindle option. If W5 is installed, the drive waits for a Start Spindle command (after power is applied) to start the spindle motor. If W5 is not installed (the factory default configuration), the drive automatically starts the spindle motor at power-on. W5 is not installed for PC/AT applications.
Sectoring The Sector/Address Mark Found signal is used to send sector pulses to the controller. Sector pulses are derived from the servo disk. The number of sector pulses generated equals:
	  20,832		   Unformatted Bytes/Sector x 3 
s = INT	(--------)	n = INT (--------------------------------)
	    n					7

	where  20,832 = frames derives from servo disk per revolution
                    s = number of sector pulses generated
 	          INT = integer part of
 	       	    n = the number of frames/sector (82 minimum)

	One frame = 1/20,832 of a revolution. 
The number of bytes per sector may be specified using the Set Bytes Per Sector command or by selecting a default sector configuration with jumpers W2, W3, and W4 as follows:
    Jumpers		Sectors			Bytes/Sector
W4	W3	W2			Formatted	Unformatted
out	out	out	   82		512		594
out	out	in	   83 *		512		584 *
out	in	out	   44		1024		1105
out	in	in	   22		2048		2209
in	out	out	   11		4096		4419
in	out	in	   58		768		839
in	in	out	  149		256		326
in	in	in	    1		48,538		48,608

* This is the default (factory installed) configuration, 
  and is recommended for PC/AT applications.

Frame Ground Option A jumper at W28 is used to connect the drive's logic ground to its frame ground. The factory default configuration, which should be used for PC/AT applications, is a jumper installed at W28.
    Jumper	Frame ground connected to logic ground.
    No Jumper	Frame ground not connected to logic ground. (Default)