Micropolis 1538-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:
	  31,248		   Unformatted Bytes/Sector x 3 
s = INT	(--------)	n = INT (--------------------------------)
	    n					7

	where  31,248 = 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)
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	   68		   512		    612
out	out	in	   71 *		   512		    582 *
out	in	out	   38		  1024		   1096
out	in	in	   18		  2244		   2314
in	out	out	   10		  4096		   4166
in	out	in	   64		   580		    650
in	in	out	  121		   272		    342
in	in	in	    1		41,594		 41,664

* 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)