 The system consists of a CMS SCSI card, Seagate ST-157N, drive case and 
 power supply from Norvac in Beaverton (local electonics supply), and a 
 cable with DB-25 to 50-pin connection. 
 
 The system price was:
 
 CMS SCSI card.......................... $115.00 + shipping
 Drive Case and Power Supply............ $125.00
 Seagate ST-157N 50-60meg............... $450.00 approx. new price
 Misc. connectors and parts............. $ 10.00
                                         -------
 Total.................................. $700.00
 
 The drive case I bought was for making a floppy or hard disk external for 
 an IBM or compatible. There is room inside for 2 half height drives and 
 the case came with a power supply and connectors for 2 drives (half height). 
 
 The CMS SCSI card came with a "hard" format, drive test, park heads, and 
 Backup II to do backups of the NEW drive. First you want to setup the 
 drive with partitions (CMS explains this) and drive ID=0. Secondly, format 
 the drive with the "hard" format and then use the PRODOS utils to format 
 the disk again (puts FAT (File Allocation Table on disk) this will be 
 needed to make the disk usable. By the way, you need to format both 
 partions to use them (32 meg max. YUCK Prodos 1.3).
 
 Then you will need the following for the cable:
    approx. 6" of 50 conductor ribbon cable
    50-pin connector crimp style
    DB-25 (RS-232 25-pin) male connector
 
 Good Luck to you all!!
 
 Dean W. Gehnert
 _____________________________________________________________________________
 DB-25 male     50-pin connector  |                Actual pin view
 ----------     ----------------  |________________________________________
   1                  48          |\1  2  3  4  5  6  7  8  9  10 11 12 13/
   2                  42          | \ 14 15 16 17 18 19 20 21 22 23 24 25/
   3                  50          |  ------------------------------------
   4                  40          |  ________
   5                  38          |  <1   2 |  NOTE: all odd pins are 
   6                  36          |  |3   4 |        grounded on a SCSI 
   7                  1*          |  |5   6 |        50-pin connection
   8                  2           |  |7   8 |
   9                  1*          |  |9   10|
   10                 8           |  |11  12|
   11                 12          |  |13  14|
   12                 14          |  |15  16|
   13                 16          |  |17  18|
   14                 1*          |  |19  20| 
   15                 46          |  |21  22|
   16                 1*          |  |23  24|
   17                 32          |  |25  26|
   18                 1*          |  |27  28|
   19                 44          |  |29  30|
   20                 18          |  |31  32|
   21                 4           |  |33  34|
   22                 6           |  |35  36|
   23                 10          |  |37  38|
   24                 1*          |  |39  40|
   25                 NC          |  |41  42|
                                  |  |43  44|
 NOTE: 1* implies a connection to |  |45  46|
       1 or any other ODD pin/wire|  |47  48|
       (which is GRND)            |  |49  50|
                                  |  --------
 ----------------------------------------------------------------------------
 
 ----------------------------------------------------------------------------
           Dean Gehnert, Tektronix Inc.  phone:(503) 627-4428
    tektronix!tekig4!deang | deang@tekig4.UUCP | deang@tekig4.LEN.TEK.COM
 ----------------------------------------------------------------------------
Article 63023 of comp.sys.apple2:
Path: caen!usenet.coe.montana.edu!netnews.nwnet.net!news.clark.edu!spool.mu.edu!bloom-beacon.mit.edu!senator-bedfellow.mit.edu!athena.mit.edu!pbauer
From: pbauer@athena.mit.edu (Paul H Bauer)
Newsgroups: comp.sys.apple2
Subject: Go Drive Info (long)
Date: 5 Oct 1993 02:36:12 GMT
Organization: Massachusetts Institute of Technology
Lines: 240
Distribution: world
Message-ID: <28qmis$gke@senator-bedfellow.MIT.EDU>
NNTP-Posting-Host: laika.mit.edu
Keywords: HD drives

Paul H Bauer (pbauer@athena.mit.edu) wrote:
:       I am trying to use a 2.5" HD from a Power Book and am looking for
: the pin outs for the two connectors on the drive. One is a 50 pos. ide
: and the other is a 16 pos ide. I assume the 50 pos is a standard SCSI
: pinout????? but what is the 16 pos, power id ?
 
Wow, you're the second person tonight looking for a GoDrive pinout....
Tomorrow, I'll make some time to type it in and post it.
But you've confused me.  If the drive came from a Powerbook, it's *NOT*
ide interface.  IDE is an interface found in Intel/DOS boxes.
And no Go-Drive has a 50 pin connector.  they have 40 + n pins,
(where 4<=n<=8).  I guess it does *look* like an IDE connector,
but electrically, it's a whole different animal.
Also, when you speak of a 16 pin connector, do you mean one into which
a little Mylar flexible printed circuit attaches, which comes out from
inside the HDA (the mechanism).  If so, these have nothing to do with
SCSI, and should be left alone.
What make/model drive are you dealing with?  That will help me help you.
---gaylon
 
**                                                                  **
** The drive I was refering to is a Conner 40 meg mechanism.        **
**                                                                  **
 
 
Gaylon R Lovelace Jr                      Process Engineer
glovelac@qntm.com                  Quantum Corp.  Customer Service
         Everything above is my opinion, not Quantum's.
 
 
Following, please find the pinout table for GoDrive SCSI.
 
Don't try and use the same +5V (or return) for both motor and logic;
t'would be bad.
 
 
**          This does not seem to be a problem              **
 
 
I'm not certain that the setup of J2 is the same for, say, a Conner
drive, but J1 should be identical.
 
**                  It seems to be the same                 **
 
In my earlier response to this thread, my brain died. I said there is no
50 pin connector on the GoDrive. This is only sort of true.  While we
think of there being two connectors, J1 & J2, they're both physically one
part. And if there weren't a bunch of missing pins, together they'd be
like a 50 pin connector.
 
Hope this helps.
----Gaylon
 
 
 
            Pinouts for Quantum GoDrive SCSI:
 
This is excerpted, sort of, from the _Go-Drive_40/80S_Product_Manual_,
    copyright 1991 by Quantum Corp.
 
 
The connector is a single 2 x 25 connector on 2mm centers for power,data
and SCSI device address.  The connector also includes four pins (pins 1-4
of J2) which are reserved as factory test points.
 
 
                 J1                         J2
Pin39                              Pin1          Pin1
|                                     |         /
o o o o o o o o o o o   o o o o o o o o   o o o o
o o o o o o o o o o o o o o o o o o o o   o o o o
|                                     |
Pin40                              Pin2
 
Recommended mating P/N:  Dupont 69764-050 or equiv.
 
**                                                                     **
**  I found 24 and 28 pos dual row 2mm connecters from Digi-Key Corp   **
**                          1-800-344-4539                             **
 
To prevent the possibility of incorrect installation, the hole of the
mating ocnnector that corresponds to pin 17 of J1 should be plugged.  Max
cable length = 12"
 
Pins 5-7 of J2 are used for hardware selectable device address as follows:
 
 
Pin 5     Pin 6     Pin 7     SCSI id
-----     -----     -----     -------
hi        hi        hi        0
lo        hi        hi        1
hi        lo        hi        2
lo        lo        hi        3
hi        hi        lo        4
lo        hi        lo        5
hi        lo        lo        6
lo        lo        lo        7
 
Pin 8 of J2 can be used to drive an LED during periods of drive activity.
 
 
Signal            Pin                     Signal            Pin
-----------       ----                    -----------       ----
+5V (logic)       1                       +5V (logic)       2
Logic return      3                       Logic return      4
GND               5                       DB0               6
GND               7                       DB1               8
GND               9                       DB2               10
GND               11                      DB3               12
GND               13                      DB4               14
GND               15                      DB5               16
KEY               17                      DB6               18
GND               19                      DB7               20
GND               21                      Parity            22
GND               23                      Termination Power 24
-ATTN             25                      -BSY              26
GND               27                      -ACK              28
-RST              29                      -MSG              30
GND               31                      -SEL              32
-I/O              33                      -C/D              34
GND               35                      -REQ              36
Motor Return      37                      Motor Return      38
+5V (motor)       39                      +5V (motor)       40
 
 
 
 
Gaylon R Lovelace Jr                      Process Engineer
glovelac@qntm.com                  Quantum Corp.  Customer Service
         Everything above is my opinion, not Quantum's.
 
 
 
This seems to be a popular topic, so here's some
more info....
 
----Gaylon
 
 
Gaylon R Lovelace Jr                      Process Engineer
glovelac@qntm.com                  Quantum Corp.  Customer Service
         Everything above (and below) is my opinion, not Quantum's.
 
 
Power Requirements for GoDrive 80S
 
Voltage                                   +5V +-5%
Current:
Sleep/Standby                             0.04A
Parked (actuator off, spindle on)         0.16A
Idle (track following)                    0.34A
Active: Reading/Writing                   0.40A
Active: Seeking                           0.44A
StartUp (peak)                            1.10A
Ripple & Noise                            50mV
 
For a one disk unit (40S, 60S, GRS 80S, GLS 85S), the peak draw at startup
is more like 0.90A.
 
I am not an expert on termination, or even on SCSI generally, or on much
of anything, to be honest.  But perhaps this info will help. In testing
operations, we use a little interface board which plugs on to the GoDrive
and presents a standard SCSI ribbon connector, so that the GoDrive and
adapter board together appear, electrically, to be just like any 3.5 inch
SCSI drive.  We have termination resistor packs on that adapter board, so
I assume that means termination must be done external to the drive.  I've
never seen the inside of a Powerbook (I'm saving my pennies), but I assume
there must be termination built onto the motherboard.
The GoDrive 40/80 S product manual (copyright 1991, Quantum Corp., etc)
says the following about Vterm:
 
  GoDrive supplies terminator power through a Schottky diode and a 1A
fuse:
 
  Vterm=
   4.25V DC to 5.25V DC
   150 mA min with 1K pullup resistors
   800mA min source drive capability, if supplying external terminators
   1.0 mA max sink capability, except when providing power to an internal
terminator
   1.0A current limiting (fuse)
I don't pretend to fully understand all the earth-shattering implications
of all those specs, but there they are.  If anyone feels able to explain
it all, feel free to followup with something on the details of SCSI
termination.
 
On the connector pinout which I posted, there separate pins for Logic
Return, Motor Return, and ground.  And I pointed out that you should
keep the logic and motor lines seperate. I just looked at two different
versions of our adapter boards, and both connect all returns to common
ground, and connect both motor and logic to a common +5V.  Personally,
I would be concerned with the motor draw pulling the logic +5 down too
low, or dirtying it up.  Perhaps that is not quite such a big worry after
all. However, I should point out that we generally use these with very
capable (big) power supplies.  Linear, not switching.  So as you put these
setups together, if you have problems with drive logic blips, think
about that ripple & noise spec.
 
The power specs should be similar for non-Quantum drives. As for extra
connectors (16 pin) on Conner drives: Quantum GoDrives are what we call
self-scan, which means the 8 hour digital scan (the last step in the
testing process which we inflict on every drive, before we ship) is run
not by an externally connected test computer, but by the microcontroller
on the drive itself.  We connect the drive to a computer, and load
all the test software onto the disk.  Then we put the drive in an oven,
with only power connected, and it tests itself.  Then we connect it to
another computer and read the test results back off the disk.
Pins 1-4 of J2 (the other end of the 2 x 25 ribbon connector) are reserved
(on Quantum drives) for signals involved in this test process.
Conner drives are self-scan, too.  Perhaps they have the extra connector
for this same sort of purpose.  Just a guess.  But whatever it is, you
shouldn't need it to use the drive.  I think....
 
 
 The GO drive that I installed internally in my GS has a peak start up
power of 685 mw and typical running power of 335 mw. This is all off of
the 5 volt supply. 13 watts off of a 5 volt supply would be about 2.6 amps
and the If you have to buy a new drive it may not be any cheaper. I found
an add from a person who had upgraded her power-book from a 40 to an 80meg
hd and had the old 40 meg drive for sale for $50. At that price I couldn't
pass it up because I had wanted to make this mod as an exercise for
several months and this provided the opertunity. I had an extra SCSI card
(RamFast C) and once I was able to get the pin-outs for the 2.5 drive
(much different than standard 3.5" SCSI drives and the 2mm connecters it
was about a 2 hour job to make the installation including an external 25
pin D connector for connecting other SCSI devices. The only caveat in this
is the SCSI has to be able to recognize a drive that has not come up to
speed when the computer is turned on since the drive is running off the
same power supply. The RamFast has this capability as well as the older
apple rev C SCSI cards I believe.
 
    If anyone is interested in doing this I can provide them with the
electrical info for the 2.5" drives.

	(SEE ABOVE)
 
       The thanks for this info goes to a very helpful customer tech rep
at Quantum Hard drives.
 



                    The do-it-yourself SCSI hard drive manual
 
                                    By Paladin
 
                                     11-6-88
 
 
 
 
 The Preliminaries
 
 This doc file will show you how simple it is to construct your own SCSI hard
 disk drive and save hundreds of dollars. There is no need to pay extra money
 for something that you can do yourself, with a little work and scrounging
 around. Do not attempt this if you don't know which end of a screwdriver to
 use. Much of the information below comes from the Apple II SCSI Card Technical
 Reference Manual and from the Adaptec ACB-5500 User's Manual.
 
 For 3 years Apple Computer and several 3rd party computer manufacturers have
 offered what is known as a SCSI card. SCSI stands for Small Computer Standard
 Interface. SCSI is pronounced "scuzzy", for those who like slang. The idea of
 SCSI is that a device can be designed to work with an interface instead of an
 actual computer.  Devices made to the SCSI standards are portable between
 systems, like external modems. In this way, SCSI is comparable to the RS-232
 serial interface. The Apple SCSI card lists for $130.00. Mail Order prices are
 about $20-30 less.
 
 The Apple II SCSI card conforms to the ANSI, x3t9.282-2 standard. The SCSI
 card is actually a small computer that runs the SCSI bus and can handle DMA in
 the GS. The SCSI card can handle 8 SCSI devices on the bus and the card counts
 as 1 device. All devices are daisy chained and must have their UNIT NUMBER set
 by a set of jumper blocks. No two devices can have the same UNIT NUMBER. The
 SCSI card should be set at a higher unit number than the disk drive; this is
 this way the bus sets priority for all the devices online and your computer
 should have top priority.
 
 Before we go much further, it must be noted that any Apple SCSI card with a
 revision "B" or earlier will NOT work with GSOS. The ROM number needed is
 #341-0437-A, also known as ROM "C". This is a free upgrade at your Apple
 dealer (see the service department product bulletins). CMS also offers a SCSI
 host card. The disadvantage of the CMS card is that it can handle only one
 drive attached to it.
 
 
 
               The Nitty-Gritty. Now for the information you want.
 
 
 Apple's version of the SCSI standard has one big difference from the real
 standard; the cable between the card and the drive uses only 25 wires instead
 of 50. Half of the wires in the 50 wire version are grounds and Apple merely
 lumped them together. The pinouts for this cable will follow shortly.
 
 The "internal" cable that connects the drive to the "outside" comes with the
 drive and is a 50 wire ribbon cable. The important thing to know is this is a
 STRAIGHT cable. Pin one from the drive goes to pin one of the connector (the
 connector is a IDC 50 contact SOCKET, 3M part #925155-50-R) and that is all
 you need to know. In fact, the cable supplied with the drive has a connector
 on the end (another 50 pin "molex") that can just stay there. Place the IDC
 connector anywhere convenient. Use a vice to crimp the connector to the cable
 being careful to align the wires with the contacts. This step is critical.
 
 
 CABLE PINOUTS
 ------------------------------------------------------
 IDC 50 contact     Signal              DB-25 Connector
 (to drive)                             (to card)
 ------------------------------------------------------
 1                  DB0-gnd             14
 2                  DB1-gnd             14
 3                  DB2-gnd             14
 4                  DB3-gnd             16
 5                  DB4-gnd             16
 6                  DB5-gnd             16
 7                  DB6-gnd             18
 8                  DB7-gnd             18
 9                  DBP-gnd             18
 11                 DIFFSENS-gnd        18
 16                 ATN-gnd             7
 18                 BSY-gnd             7
 19                 ACK-gnd             7
 20                 RST-gnd             9
 21                 MSG-gnd             9
 22                 SEL-gnd             9
 23                 C/D-gnd             24
 24                 REQ-gnd             24
 25                 I/O-gnd             24
 26                 -DB0                8
 27                 -DB1                21
 28                 -DB2                22
 29                 -DB3                10
 30                 -DB4                23
 31                 -DB5                11
 32                 -DB6                12
 33                 -DB7                13
 34                 -DBP                20
 38                 TERMPWR             25
 41                 -ATN                17
 43                 -BSY                6
 44                 -ACK                5
 45                 -RST                4
 46                 -MSG                2
 47                 -SEL                19
 48                 -C/D                15
 49                 -REQ                1
 50                 -I/O                3
 -------------------------------------------------------
 
 This cable can be had at the swap meets for $6.00 to $15.00. Beware of
 __some__ MAC+ SCSI cables. They sometimes only have 6 ground wires
 connected to the 50-pin connector (at least my MAC+ cable was done this way)
 and the drive will not work. If you get one that has this problem, 10 minutes
 with a soldering iron will fix it. Also avoid molded ends on any cable you
 buy; you may have to modify the wiring. A GOOD knowledgable cable company
 should be your source. Belkin Components in Gardena, California is one good
 source.
 
 
 
 
                                  The HARD FACTS
 
 
 You now have the SCSI card and cable (external). You are about 40% finished.
 Now for the drive. One of the best places to find SCSI drives is in the
 Computer Shopper. Most disk drives advertised are for the IBM and are the
 ST412/506 type drives which are unusable for our project. The ad must state
 SCSI drives before you can even concider the company selling the drives. 90%
 of the people selling drives are so IBM oriented they think "scuzzy" is a
 BRAND of disk drive! Forget these people. They will be of little help. Stick
 to the companies that sell JUST drives or list SCSIs. They'll know what you're
 ordering. I bought mine through Hard Drives International in Phoenix, Az and I
 recommend them.
 
 While every major hard disk manufacturer makes SCSI drives I will list the
 Seagate models so you can get an idea of what is available. The Seagate SCSI
 drives have a "N" as a suffix to the model number.
 
 Model    Capacity  Sectors   Access Time         Power Comsumption
          (Mbytes)            (millisecs)              (watts)
 -----------------------------------------------------------------------------
 (5 1/4" half height)                                     (apprx $ 11/88)
 
 ST225N   20        41,720    65                  17                $319
 ST251N   43        84,254    40                  13                $419
 ST277N   64       126,790    40                  13                $449
 ST296N   80       158,320    28                  13                $899
 
 (3 1/2")
 
 ST138N   32        63,139    28                  12
 ST157N   48        95,015    28                  12
 -----------------------------------------------------------------------------
 
 
 You will notice that there were no specs on the number of cylinders, heads and
 other commonly used data. They are not neccessary with the SCSI drives; they
 are "intelligent" drives and they "know" how big they are.
 
 
 
                                 The Missing Case
 
 
 Now you have the SCSI card, drive and the cable. Now for the case and the
 power supply.
 
 If you have an old Rana or Corona hard disk then you're in luck, although any
 old hard disk enclosure/power supply will also do quite nicely. Just remove
 the drive, controller card (that strange card that sits on top of the drive,
 if
 there is one.) and cable. You will not need any of this. Set the unit number
 (remember this at the beginning of this doc?) of the new drive, plug in the
 power supply to the drive and then mount the drive to the base (don't force
 the
 drive to fit if the holes don't line up!). Run the SCSI cable out the back
 making sure the clamp holds it tight. Replace the top. Plug in the SCSI card
 (the Apple's power is off...RIGHT?). Plug everything together, making sure the
 connections are good.
 
 (Warning for the following paragraph: I have not personally tried the ideas
 presented next. It has been pointed out to me that the Apple power supply may
 be a little too weak on the +12v side. It has only 1 amp available and the
 spindle motor for the hard drive MAY require more. It is a marginal situation
 which YOU will have to decide upon.)
 
 If you don't have an old drive (we're talking ancient stuff here..old 5 & 10
 meg drives) that you're willing to sacrifice, here's a novel idea. Find that
 old Apple II+ laying in the closet. Rip out the motherboard. Find two holes
 that line up with the drive or drill the holes for the drive. Get a hard drive
 power connector (it's a very standard connector at a GOOD electronics store).
 Splice in the connector to the Apple II+'s power supply (pin outs below) and
 plug it in (WARNING! I WILL NOT BE RESPONSIBLE FOR ANY DAMAGE DONE HERE! I
 RECOMMEND YOU CHECK EVERYTHING THROUGHLY BEFORE POWERING ON. I HIGHLY
 RECOMMEND YOU HAVE AN OHM METER/VOLTMETER HANDY FOR ALL OF THIS). The rest is
 just like the previous paragraph.
 
 
 Pinouts for the Apple power supply
 ----------------------------------
       ____
 _____|   |____
 |/           \|
 |  O 5    O6  | pin 5 = -12 V, pin 6= -5 V
 |_           _|
 |_ O 3    O4 _| pin 3 = +5 v, pin 4= +12
 |             |
 |  O 1    O2  | pins 1 & 2 are grounds
 |______|______|
 
 (please excuse the artwork!)
 
 Pinouts for HD power connector
 ------------------------------
 
  ______________________
 /                      \  Pin 1= +5 v
 |  O1    O2   O3   O4  |  pin 2 & 3= ground
 |______________________|  pin 4= +12 v
 
 
 As you can see, pin 3 from the Apple PS goes to pin 1 of HD and pin 4 from the
 SP goes to pin 4 of the HD and both or either pins one and two can go to pins
 2
 & 3 of the HD. All the views are from the socket/plug ends and not from the
 back.
 
 OK, so you don't have either an old drive or an old dead Apple. If you can
 afford it, look in the Computer Shopper for Hard Drive cases. They come
 complete with power supply, fan, spike/overvoltage protector, painted case,
 mounted front light, ect. Prices range from $85 to $170. This is the sane way
 to go. I have bought the Tulin "Apple Hive" case and can recommend it. Some
 things are a little "Mickey Mouse" but they are otherwise useable (like the
 power switch and the busy light not done right).
 
 Otherwise you are going have to be very good at scrounging! What is needed
 here is a 25-40 watt switching power supply (a regular tranformer type may be
 a little too big but that's your decision) with +5, +12, and a ground. These
 power supplies can be found in most electronic surplus stores for $15-30.
 Timeline in Gardena is a good source for power supplies. $12.00 will get you a
 180 watt power supply that's a little bigger than an Apple II unit (it has no
 case, switch, cord, ect). Sometimes you can buy a whole electronic doo-dad
 that has both a power supply and a case for $20-30, so search around.
 
 Now for the moment of truth; turn on the drive. It should whine and click away
 for about 20-30 seconds and then settle into a constant speed. Flip on the
 Apple. If you have plugged the SCSI card into slot 7 there will be a slight
 delay while the machine polls the SCSI card and drive. THIS IS GOOD, DON'T
 PANIC! You should hear the drive searching for Prodos or anything else. If the
 machine hangs (over 30 seconds) then something is wrong with the connections
 or
 the UNIT NUMBERS (remember these?...again!) or there is a major DOA part.  If
 it doesn't find anything the Apple will boot the next controller card it
 finds.
 If the drive light went on while prodos/gsos was booting then you're home free
 and you can continue to the next section. If nothing happened the you need to
 double check EVERYTHING to see if anythings wrong.
 
 Just a little word of encouragement. As long as the drive does it's
 "self-test" when you power it on, it is OK. I even plugged my unit in
 backwards (the SCSI cable) and it didn't effect it (however, this is not
 recommended). The problem will most likely the connector on the ribbon cable.
 If you have a version A or B SCSI ROM make sure to get it exchanged for the
 version C ROM, in any case.
 
 
 
 
                                The software side
 
 You will find out that the SCSI Utilities disk from Apple  (running under
 Prodos 8) will only recognize volumes of 20 megs, and, depending on the slot
 the host card is in, will only partition 2 or 4 volumes maximum. If you have
 the drives bigger than 40 megs you'll either have to leave the host card in
 slot 5 (allows phantom drives in slot 2, equals 4 drives or devices) in order
 to get more than 2 partitions of 20 megs each, OR, the smart move, to find a
 friend with a GS and GSOS (using the ADVANCED DISK UTILITIES) and have the
 partitioning/intializing done on the GS. This will allow you to partition the
 drive with 32 meg volumes (or any size you want. But Prodos still will only
 recognize 32 meg volumes; anything over that is a waste of space). GSOS will
 also allow partitioning far beyond what Prodos will recognize. In fact, Prodos
 will only recognize 8 devices total (disk drives), while GSOS can partition
 more than that. Each partition counts as one device. The partition is
 initialized after the partitioning is done.
 
 So let's review:
 
 Set the unit number of the hard drive (installation book that comes with drive
 will explain how)
 
 Install 50 pin (Centronics 50 pin socket) onto the 50 conductor ribbon cable,
 pin one of drive going to pin one of connector.
 
 Make of buy the SCSI "system" cable using the pinouts from above. It has a
 male DB-25 on one end and a 50 pin male Centronics on the other.
 
 Plug in SCSI card into any slot but 3 (making sure the unit number is set per
 Apple's instructions).
 
 Connect cables. (make power cable if you don't have the "stock" setup of
 another drive to start with).
 
 Power on and wait for the drive to self-test. Power on Apple. Use SCSI
 Utilities or ADVANCED DISK UTILITIES to partition/initialize disk.
 
 When you've done that, you're finished! Now you can transfer files onto the
 drive, create subdirectories and anything else you do with a HD. You can take
 pride in the fact you BUILT this system and saved $$$ while doing so.
 
 =============================================================================
 
 A side note: I highly recommend Prosel for your new hard drive. It is worth
 every penny of the $40 price tag. Glen Bredon is the author/publisher of
 Prosel.
