third party hard drives ...

Thu Mar 29 01:30:43 AEST 1990

   We bought a Hitachi DK514-38, ESDI drive for our 3130 to replace the
DK512-17 we already have.  (We bought this drive on the recomendation of
a SGI technical person.) I got technical information on both drives and
almost got it to work.  Actually, if I don't want to use the 1/4"
cartridge tape drive the new drive worked ok, but the moment I tried to
use the tape drive, I got hard disk errors.  It turns out that the DK514-38
is too fast a drive for the Storager II board in the 3000's.  Interphase
(the manufacturer of the Storager II board) said their Storager III board
would work with the drive.  I owe a great deal to the people at Interphase
they helped me out a lot.  With out them I wouldn'd have been able to get as
far as I did.  Our local SGI field technitian did try to help, but couldn't
come up with any solutions.  I do thank him for trying.
   The best advice I can give you is to check with who ever you bought
the drive from and get a Product Specification and/or Service Manual for
both drives, preferably the Product Specifications.  This makes life a
whole lot easier.  I will try to give you some pointers.  After you do
this a few times things become obvious, that when you started weren't at
all obvious.

DK512-17:

     Selecting    Sector / Byte Clock / Address Mark Found:
     Jumper plug JP32A

          1 [--] 22    Sector-N
          2 [--] 21             (both jumpers in)

          1 [--] 22    Byte CLOCK
          2 [  ] 21

          1 [  ] 22    Address Mark Found-N
          2 [--] 21

          1 [  ] 22    Diagnostic Mode
          2 [  ] 21             (both jumpers out)
          (Our drive had both jumpers in, Sector-N selected)

     Selection Bytes/Sector and Sectors/Track:
     Jumper plugs JP22 & JP32

          Jumper Plug #     Jumper Plug Key #     # of bytes
	      JP22              1-16                   1
	      JP22              2-15                   2
	      JP22              3-14                   4
	      JP22              4-13                   8
	      JP22              5-12                  16
	      JP22              6-11                  32
	      JP22              7-10                  64
	      JP22              8-9                  128
	      JP32             11-12                 256
	      JP32             10-13                 512
	      JP32              9-14                1024
	      JP32              8-15                2048
	      JP32              7-16                4096
	      JP32              6-17                8192
	  (Our drive was set to 652 bytes/sector, however when
	   you run the formatting program it is 512 bytes/sector
	   and you specify how many sectors/track you want)
	   You need to know how many bytes/track your disk has,
	   then divide that by the number of sectors you want per
	   track this will give you how many bytes/sector you will
	   set on the jumpers.  This is a number >= 512 for the SGI
	   machines.  This was the hardest part for me to get right.
	   At the end I had 708 bytes/sector and 42 sectors/track
	   on my DK514-38, this drive has 30,240 bytes/track unformatted.
	   So I had the jumpers set to 708 bytes and when I formatted
	   the drive I specified 42 sectors/track.
	   Note: the terms "track" and "cylinder" are used
	   interchangeably in documentation.

     Drive Selector Jumper:
     Jumper plugs JP32 & JP32A

	  Drive # 1     Drive # 2     Drive # 3
          3 [--] 20     3 [  ] 20     3 [--] 20
          4 [  ] 19     4 [--] 19     4 [--] 19     etc....
          5 [  ] 18     5 [  ] 18     5 [  ] 18

	  (start numbering drives from 1, drive number 0 is not valid)

     Setting Device Type:
     Jumper plug JP39

          1 [  ] 4    DK512-17
          2 [  ] 3             (both jumpers out)

          1 [--] 4    DK512-12
          2 [  ] 3

          1 [  ] 4    DK512-8
          2 [--] 3

          1 [--] 4    Reserved
          2 [--] 3             (both jumpers in)
	  (Ours was set to DK512-17)

     Setting/Resetting Write Protected:
     Jumper plug JP172

          1 [--] 4    Drive is always read only.
          2 [  ] 3

          1 [  ] 4
          2 [--] 3
             or       Drive is always read/write.
          1 [  ] 4
          2 [  ] 3
          (Ours was always read/write, jumper 2&3 in)

     Setting Motor Start/Stop Option:
     Jumper plug JP33A

	  [ --]      Motor start/stop is controlled by command.
	   321

	  [-- ]      Motor start/stop is controlled by power on/off.
           321
	  (Ours was controlled by power on/off.)

     Termination Networks:
	Termination networks terminate the control signals line (J1).
	Should be labelled MR24, looks like an IC and is near the J1
	connector.

	.  In star (radial) systems, leave termination networks in
	   all drives.

	.  In daisy-chain systems, remove the termination networks
	   from all drives except the drive at the end of the chain.

	Our 3130 is daisy-chain, so drive 1 SHOULD have had the termination
	network removed and drive 2 should have had it installed. However,
	the termination networks were in both drives.

	(Note: star systems have a separate J1 connector for each
	       drive.  In daisy-chain systems J1 goes from on drive
	       to the next.)

   I hope this is of some help.  There have been some rumors that SGI
puts custom ROMs in their drives.  Based on the success I have had I
would say that rumor is false.  Also, the DK514-38 will not work on a
3130, if you also have a 1/4" cartridge tape.
--

	Brent L. Bates
	NASA-Langley Research Center
	M.S. 361
	Hampton, Virginia  23665-5225
	(804) 864-2854
	E-mail: blbates at aero4.larc.nasa.gov or blbates at aero2.larc.nasa.gov