bobl@pro-graphics.cts.com (System Administrator) (08/27/89)
Introduction
With the advent of cheaper memory, larger software and especially
the Apple //gs, Apple // computer users are using their systems for
more complex and larger tasks resulting in greater demands for high
capacity disk storage systems. Since the birth of the Apple ][, we
have seen changes in disk storage from the original 13-sectored 5.25
inch floppy drive, to the 16-sectored 5.25 inch floppy drive (160K
maximum capacity), to 3.5 inch micro floppy (800K maximum capacity) to
the rise in popularity of hard disk drives from 5 megabytes capacity
on up. These changing demands are not Apple //-specific but are
common throughout the industry, and the advances in hard disk drive
technology have been coupled with ever-decreasing costs. Where once a
hard drive was the property of the wealthy few, more and more "home
users" are finding hard drives are no longer dreams of their futures
but realities in their dens and living rooms.
When I purchased my Sider 10 meg SASI hard drive in April 1986, I
paid $695 "mail order". When I purchased my 60 meg CMS SD60 A2S SCSI
hard drive in January 1988, the mail order price was $950. As you can
see, the price per megabyte storage decreased from 69.50/meg to
$15.83/meg - quite a price decrease! And although the price of
commercial hard drives has not decreased very much in the year since I
purchased the CMS drive, you can easily assemble your own SCSI hard
drive at a cost of about $10.93/meg for a 64 meg SCSI drive! I'll
explain how (and how easy) it is in this document.
Why a SCSI Drive?
For Apple // owners, there are basically two types of hard disk
drives which are popular: SASI and SCSI. And example of a SASI drive
is the Sider series by XEBEC (formerly First Class Peripherals), and
examples of the SCSI drive are the CMS, Chinook and Apple hard drives.
The SCSI (Small Computer Systems Interface) hard drives are by
far the most popular devices these days, especially in light of
Apple's committment to the SCSI interface (also used on the Mac line).
The SCSI interface allows you to chain several SCSI devices on the
same "chain", and both ProDOS and GS/OS were designed with the SCSI
interface in mind. To keep pace with future design advances in CPU
and software, it is highly recommended that you choose the SCSI
interface type hard drives for your system.
Which Brand SCSI Hard Drive Do I Choose?
There are several manufacturers of SCSI hard drives of excellent
quality: Seagate and MiniScribe are, in my opinion, two of the best
around. Both manufacturers market a wide array of drive types (SCSI,
MFM, RLL), capacities (10-345 megs) and speeds (65-19 milliseconds)
and provide very high quality products backed by a 1-year
manufacturer's warranty. The CMS drives, for example, use the Seagate
SCSI series of drives in their products.
When searching for a SCSI hard drive, the first thing you need to
know is how to identify a SCSI drive from another interface type (such
as MFM or RLL). Seagate's SCSI hard drives are identified by numbers
beginning with "ST" and ending in "N"; for example, the Seagate 20 meg
SCSI drive is identified by ST255N, their 40 meg SCSI drive by ST251N
and their 65 meg drive by ST277N. MiniScibe identifies their SCSI
hard drives by a 4-digit number followed by "S"; their 20 meg drive is
identified by 8425S and their 40 meg drive by 8051S.
Which Size Drive Do I Choose?
Which drive you choose depends upon several personal factors,
such as total storage capacity you need and the types of applications
you'll be running at present, what you think your future needs will
be, and how much money you can afford to spend right now.
Your present needs and applications are the easiest thing to
determine. Consider how many 800K micro floppies and 160K 5.25 inch
floppies you have as "work disks" (vs backups) and calculate the total
storage capacity that all of these collectively take to get a rough
idea as to what your present hard drive useage would be. Consider how
fast you accumulate disks - 10 per month, 50 per month? Most of your
disk accumulations should be for data, since most folks do not
accumulate program disks anywhere near as fast as they do data disks.
Next, consider which of all your programs you would actually be
running off the hard drive. Note that many games are copy-protected
and thus can not readily be moved to hard disk unless (a) you can
remove the copy protection (or in rare cases, the copy protection only
applies to floppy copies and the copy protected program can be moved
to high capacity storage devices) and (b) the program was written such
that it is not dependent upon a specific volume name "hard coded" into
the program itself (if it does require a specific volume name, even
when run off the hard drive, it will require the floppy to be in the
drive and will most likely use that version rather than your hard
drive version). All of these considerations are guidelines for
getting some rough idea as to your current hard drive needs; the
bottom line is that you will have to give serious thought to exactly
what it is you'll be putting on your hard drive.
The hardest thing to determine is what your future hard drive
needs will be. This is especially difficult because, in many regards,
the requirements of future software applications is not only out of
your hands but remains unknown to even the developers themselves! If
you are using an Apple //gs, about all that can be said is that
software is growing at an unbelievable rate and even now many
//gs-specific products come on multiple 800K microfloppies. Look to
the Mac and MS-DOS and OS/2 worlds to get a taste in the trends:
single applications requiring a dozen or more high density floppies
are not uncommon by any stretch of the imagination.
Just like buying a new car, determining what you can afford on a
new hard drive is extremely difficult in large part because the cost
per megabyte of storage decreases dramatically as the overall capacity
of the drive increases. For example, ComputAbility's prices for
Seagate SCSI hard drives in February 1989 were $319 for 20 megs and
$419 for 65 megs: $15.95 per meg vs $6.45 per meg. Considering the
per meg cost, it really does pay to stretch your wallet to the max and
get the largest hard drive you can possibly afford if you're looking
for both the best dollar value and the maximum expandability for the
future.
Finally, consider the sizes of the data files with which you'll
be working, and their number. Many database programs, for example,
use "virtual memory" - using the disk in lieu of RAM memory. An
example of such an application is Managing Your Money. Applications
which use virtual memory require not only disk space for the file but
more (which can be double the size of the disk file itself) for
virtual memory. Again, there is no global rule-of-thumb for this - it
varies from user to user based on specific software applications
running and the amounts of data being maintained and manipulated.
What Speed Drive Do I Need?
To the greatest majority of folks, Speed Is King. In addition to
large storage capacity (and the concomitant elimination of constant
swapping of floppy disks during your application), hard disk drives
offer great improvements over floppies in I/O (input/output) times.
Several factors play a role in the effective I/O speed of the device:
seek time (how fast the drive itself can find specific blocks on the
disk surface), transfer rates (how fast the data can be moved between
drive and computer), and CPU speed (how fast your computer can handle
data movememts within itself).
"Slow" hard drives have a speed of approximately 60 msec or
greater. "Fast" hard drives have speeds in the range of 18-28 msec.
The most common "average" SCSI hard drives operate in the 40-42 msec
range. Of course, you pay for increased speed (nothing is free in
life), and to give you a rough idea of how much you pay for the speed
increase, consider these prices from Hard Drives International on
identical type (non-SCSI) and sized drives which differ ONLY in access
speeds: the Seagate ST251 40 meg drive at 40 msec runs $329 whereas
the exact same drive running at 28 msec is $399. That's $1.75/meg
added to the cost for increased speed alone.
The most popular speed today on the Apple // series is 40 msec
since neither the CPU nor the host adapter cards (plugged into the
Apple's slots and connected to the hard drive itself) can handle
drives much faster than this. Of course, this will change in the
future, but for now spending more money on drives faster than 40 msec
does not give you any direct benefit. If today is your main concern,
you are better off spending the extra dollars to get a larger capacity
drive; if you are concerned with tomorrow as well, and speed is your
main concern, getting the faster drive today may pay off in the near
future. About the only other suggestion I can offer is to NOT get a
drive slower than 40 msec (i.e., an access time whose number is
greater than 40, e.g., 65 msec).
Rolling My Own - A Short History
Last year, when my BBS needed to expand its hard drive storage
beyond the 10 megs it had, I was faced with again spending $950 for
another commercially-available 60 meg hard disk drive. And my pockets
just weren't that deep, especially after having blown $950 several
months earlier. I was also somewhat green with envy at all my MS-DOS
friends (yes, I admit it - I do have MS-DOS friends!) constantly
bragging about just how cheap their hardware was. These were the
circumstances which lead me to buy my first copy of Computer Shopper
and thus began my journey into the unknown world of assembling my own
vanilla SCSI hard disk drive.
Having a CMS drive already, I popped open the hood and looked
inside. I found that the CMS hard drive - once mysterious and magical
- was nothing more than a Seagate ST277N SCSI drive and power supply
unit inside a metal box. It appeared that CMS did no alterations
whatsoever to the Seagate drive itself; that is, all of the
interfacing to my Apple //gs was done via their SCSI Host Adapter card
which plugs into a slot inside the Apple itself. Time to call in my
chips with all my contacts in the industry, so off I went through
CompuServe, GEnie, a series of telephone calls and numerous letters.
To my surprise, no-one seemed to know if my assumptions about the CMS
were correct. I was on my own, with a lot of "Best wishes and let me
know how you make out!"
I obtained a loaner Seagate ST277N in plain, no-frills case with
power supply. I replaced my CMS drive with this generic drive and
booted the system. After several attempts, I got it to work
flawlessly off the CMS SCSI Host Adapter. My suspicions were indeed
true!
Out came the Computer Shopper and in went my orders to vendors.
Here's the hardware I went with and highly recommend:
Hardware Required
- Seagate STxxxN SCSI hard drive. I used the exactly same 66 meg
drive that CMS uses in their 60 meg SD60 A2S model (the difference in
size is explained below; the drive itself is indeed 65 megs
unformatted capacity)
- The Tulin Apple Hive case with 30 meg power supply, fan and all
internal cables and hardware.
- The CMS SCSI Host Adapter Card with external cable and
formatting software.
As of the February 1989 advertised prices in Computer Shopper,
this same drive subsystem will run approximately $653 without shipping
if you use the ST277N model (65 megs). I supply a list of vendors and
February 1989 advertised prices at the end of this document; you can
bargain hunt through Computer Shopper and local computer faires and
flea markets and save a few extra dollars if Lady Luck is on your
side.
The Roll
Assembly is truly a piece of cake if you have mastered the fine
art of using a Phillipshead screwdriver, and total hardware assembly
time is less than 5 minutes (taking your time). Since all cases are
basically identical in terms of assembly of the unit, I will be
relying upon my personal experience using the Tulin Apple Hive here.
Secure the Seagate drive to the base of the case using the
supplied 4 screws and tighten securely but be careful not to exert too
much torque (if this is at all possible). Take one of the two power
cables coming from the power supply and plug it into the back of the
drive itself. The power line terminates in a D-shaped male connector
which plugs into a D-shaped female socket on the back of the drive;
the D-shape prevents you from plugging the power cable into the drive
in the wrong orientation, so this is fool-proof. Next, plug the cable
coming from the twin DB-25 pin connectors on the back of the case into
the drive. This cable terminates in a 50-pin connector. Examine this
connector closely and you will note that there is a guide on it which
will allow you to insert it onto the connected on the back of the
drive ONLY in the proper orientation, so you can't possibly install
this cable wrong. Next, examine the 4 sets of pins on the lower left
back side of the drive itself. If any of these pairs have jumpers
(small black plastic tabs which slide over a pair of pins), remove
them. Without too much discussion on their function, suffice it to
say that without any of these pin sets "jumped", the drive will have a
device number of 0 (zero). Next, connect the two single-stranded
lines running from the power supply to the green LED light on the
front of the case. This light is the power ON/OFF indicator.
Finally, replace the top of the case, securing to the base with the 3
screws provided, and insert the external power cord into the back of
the case (but don't plug it into the wall just yet). Assembly of your
hard drive system is now complete and ready for attachment to your
Apple //.
How you interface your SCSI to your Apple depends upon the
specific host adapter card you are using. In this example, I'm using
the CMS SCSI Host Adapter card; if you are using another brand card,
follow the manufacturer's directions for setting up the card. You
will need to know that your hard drive has a device number of 0
(zero).
The CMS card is configured using jumpers (exactly like those
which may have been on the back of your Seagate drive that you
removed). These jumpers control such things as capacity of the drive,
volume partitions (start locations and size), device number, etc.
Note that GS/OS will allow you to access volumes greater than 32
megabytes but if you are using any ProDOS-8 or ProDOS-16 applications,
you must partition your drive so that no single volume exceeds the
ProDOS limitation of 32 meg maximum volume size. Thus, in this
example, we'll be partitioning the drive into 2 30 meg volumes.
The CMS card has 6 banks of 8 pairs of jumpers to control Device
ID (DID), Host ID (HID), Partition Starting Point and Size (PS1 and
SZ1) for the first partition and Partition Starting Point and Size
(PS2 and SZ2) for the second partition. Since we set our drive to a
device ID (DID) of zero, none of the pin pairs should be jumped. To
select a host ID (HID) of 7, the first 4 pin pairs (1-4) should be
jumped and the last 4 pin pairs (5-8) should be open. Our first
partition will start at a location of zero and be 30 meg in size, so
the jumper settings for PS1 should be all open (none jumped) and SZ1
should have jumpers ONLY on pin pairs 1, 3, 4 and 5 (pin pairs 2, 6, 7
and 8 should be open). The second partition will begin at location 30
and be 30 megs in size, so the jumper settings to accomplish this are
PS2 should have a jumper ONLY on pin pair 4 (all others are open) and
SZ2 should have jumpers on pin pairs 1, 3, 4 and 5 ONLY (2, 6, 7 and 8
are open).
Having set the card for the correct configuration, insert the
card into an open slot in your Apple // (6 or 7 is preferred), connect
the short ribbon cable coming from the card to the back of the // at
an open panel in the back plate. Connect one end of the heavy-
shielded cable supplied with the host adapter card to the DB-25
connector at the back of the Apple and the other end to one of the two
(either one) DB-25 connectors on the back of the Apple Hive case.
Make sure all connections are secure. Plug the hard drive power cord
into a wall socket and turn the hard drive ON using the ON/OFF switch
on the front of the Apple Hive case. Put the utilities disk supplied
with the host adapter card into your floppy drive and boot your
computer.
Before you can use your hard drive, you must perform two tasks.
One is the "low level" formatting of the disk surface itself. The
software to do this is supplied on the CMS utilities disk that comes
with the Host Adapter card. The other task is the ProDOS formatting
of the drive, which is done after the low level formatting.
Use the CMS Utilities Disk to low-level format the new drive
surface. This will take several minutes to perform. When done, it is
an excellent idea (not really an option in my opinion) to run the test
procedure. This test procedure performs read/write activity on each
and every block on the disk surface repeatedly until you stop the
test. It takes quite a bit of time to do one "pass" - that is, to
read/write/verify every block on the disk - and it is recommended you
let this procedure do several passes. Take the time to do this, since
the procedure will mark as "unavailable" those bad blocks it finds and
this will prevent you from loosing valuable data in the future. Don't
worry if your system turns up several bad blocks - hard drives all
have bad blocks, and thus the manufacturers allow extra tracks on the
disk for replacement blocks.
After the test for bad blocks has been performed, you can exit
the utilities and you're ready for the last step in preparing your
hard drive for use: the ProDOS formatting. I use Prosel's CAT.DOCTOR
utility exclusively (more on this later) but any utility which allows
you to ProDOS format a disk will do. Run your ProDOS format utility
and select S6D1 (assuming your hard drive host adapter card is plugged
into slot 6) for formatting. You will see that this takes less than 2
seconds to perform! Next, select S6D2 for formatting. Remember, we
had to partition the drive into 2 30 meg volumes, and these are mapped
as Drive 1 and Drive 2 in the slot in which your host adapter card is
plugged into. You can name each of these volumes with any valid
ProDOS volume name, such as /HARD1 and /HARD2.
Congratulations! Your hard drive is now fully ready to use.
Where Do I Order From?
In addition to the vendors that I have purchased from, there are
several others advertising in Computer Shopper. Here is a list, by no
means exhaustive, of some of the dozens of vendors selling various
hardware you'll need:
Hard Drives International (1-800-234-DISK) is an extremely
reputable firm dealing ONLY in hard drives. HDI provides near rock
bottom prices, usually delivers quickly (if item is not out of stock),
and provides a full technical support team. Here are prices for some
of the more popular Seagate and MiniScribe drives, as advertised in
Computer Shopper February 1989:
- MiniScribe 8425S 20 meg 65 msec $299
- MiniScribe 8051S 40 meg 28 msec $449
- Seagate ST225N 20 meg 65 msec $299
- Seagate ST251N 40 meg 40 msec $399
- Seagate ST277N 65 meg 40 msec $449
- Seagate ST296N 80 meg 28 msec $699
ComputAbility (1-800-558-0003) offers rock bottom prices:
- Seagate ST225N $279
- Seagate ST251N $375
- Seagate ST277N $419
- Seagate ST296N $699
Tulin Corporation (1-408-432-9025) provides an excellent case -
sturdy and quite attractive - in the Apple Hive. The Apple Hive cases
come complete with power supply, fan and ALL internal hardware and
cables necessary - you only need to buy a drive. They also now
provide "kits" including everything (except the SCSI host adapter
card) needed:
- Apple Hive with 30 watts power + fan $119
- Apple Hive with 60 watts power + fan $169
- 30 meg SCSI Drive System w/ Formatting Software $425
- 40 meg SCSI Drive System w/ Formatting Software $489
- 61 meg SCSI Drive System w/ Formatting Software $529
* SCSI Drive Systems do NOT include host adapter card
* Each Seagate SCSI drive (STxxxN) requires 12.5 watts power
so the 30 watts Apple Hive will sufficiently power two
hard drives.
HardTimes (1-408-452-1929) offers an inexpensive alternative to
the Apple Hive case by Tulin. The HardTimes case ($79) features a
fan, 50 watts power supply, brackets, room for 2 half-height or 1 full
height drive and room for a controller. (*Note: the Seagate STxxxN
drives contain a SCSI controller embedded within the drive and do NOT
require an external controller board.)
CDA Computer Sales (1-800-526-5313) is an excellent source of
SCSI host adapter cards, both CMS and Apple. Both brands run
approximately $115. CDA provides excellent service and is reliable
and priced competitively.
Alternative Life Styles
You do NOT absolutely need to get a hard drive mechanism with
SCSI embedded. Adaptec markets controller cards which allow you to
use MFM or RLL hard drives off an Apple SCSI host adapter. The basis
for this card (Adaptec 4000 series) is that the card is positioned
between the drive mechanism itself and the host adapter card in the
link. The non-SCSI drives generally can be had for about $80 less
than their SCSI counterparts, but then you need to shell out
approximately $100 for the Adaptec card; its therefore usually
cheaper, and a whole lot neater, to simply obtain a SCSI drive. But
if you're lucky enough to obtain a non-SCSI drive for free, you can
indeed use it with the proper Adaptec card. Hard Drives International
is the best source of information on the Adaptec cards, so give them a
call.
Miscellany
If you opt for the HardTimes or other brand case, other than the
Tulin Apple Hive, you may be faced with needing to order a cable or
some other internal hardware. Before you ask, tell the vendor exactly
what you'll be using the case for and ask what internal hardware
(cables, brackets, etc.) is provided and what is not provided (and
thus what you will need to secure elsewhere). In this sense, the
Tulin Apple Hive is the easiest, most hassle-free case to get.
In case you find the need to make your own cable, I provide the
pinouts below. Seagate provides a short 50 line ribbon cable,
terminating at both ends in a 50-pin connector. Thus, you may need to
make (or otherwise obtain) a heavy-shielded cable going from 50-pin at
one end (drive end) down to DB-25 pin at the other end (computer host
adapter end). If you're not good at soldering, or simply
faint-of-heart, Mytech (1-800-527-7435) might be able to provide you
with exactly the cable you need at extremely reasonable prices.
The pinout needed for the SCSI external cable (host adapter to
drive) is as follows:
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|
| --------
Apple II SCSI Card: Spec Sheet
I. Technical Specifications
A. Hardware:
-- Provides an electrical interface between external SCSI devices
and the CPU.
-- Provides the address and control lines required by the Apple
II's microprocessor for accessing and controlling the SCSI chip
and Smartport firmware.
1. NCR 5380 SCSI IC
a. Implements SCSI bus
b. 5380 data sheet in Chapter 2 of the hardware technical
reference manual
2. Other circuitry to interface the 5380 IC with the Apple II CPU
control signals
3. RAM:
-- 8 banks of 1K
-- Accessed with special logic circuits
-- Used for status of devices at SCSI bus initialization
(including the status of the Apple II SCSI card itself)
4. ROM:
-- 8 banks of 1K
-- Accessed with special logic circuits
-- Used for storing Smartport firmware
5. Interface: 25-pin SCSI connector
B. Input/Output:
-- Parallel transmission
1. Two modes for data i/o operations:
a. PDMA (pseudo-DMA)
-- default
b. Block Move
-- only supported by 65816 CPUs
-- must be enabled by the application
2. Maximum storage area under ProDOS: 32 megabytes
C. Firmware: Smartport program
-- converts the microprocessor commands or calls issued by CPU to
format compatible with external SCSI devices
-- issues calls to the microprocessor to give it the status of the
external SCSI devices and allow the CPU to control their
operation
1. Commands supported: STATUS, READ BLOCK, WRITE BLOCK, FORMAT,
CONTROL, INIT, OPEN, CLOSE, READ, WRITE
2. Boot capablility with Autostart ROM when you install the card in
the slot with highest priority, which may depend on the
operating environment
-- When Smartport does not find the SCSI device capable of
booting the system, Smartport returns control to the
environment of the Apple II and the boot search continues
through lower-priority slots.
D. Electrical
1. Voltage requirement: 4.75 to 5.25 volts DC
2. Power consumption in milliamps (ma)
a. Standby: 340 ma
b. Operating: 390 ma
E. Environmental
Degrees
Celsius Fahrenheit
1. Ambient temperature: 10 to 40 50 to 104
2. Relative humidity: 20 to 95 percent (noncondensing)
II. System Configuration
A. Cable: Apple SCSI System Cable
B. One or more SCSI-compatible peripherals
-- Can be a high-speed printer interface
1. Daisy chaining
-- Apple II with the card in slot 5 and no card in slot 2,
except a card for a serial printer or modem:
a. Running ProDOS 1.2: 4 external devices
b. Running ProDOS 16: 7 external devices
C. Additional SCSI system components as required:
1. Cable Terminator
2. Peripheral Cables
3. Cable Extenders
-- Maximum total length of cables: 20 feet (6.5 meters)
Important: Read the manual for the Apple SCSI Cable System
before trying to connect any devices
D. Computer with disk drive
-- Apple IIGS
-- Apple IIe
-- Apple II Plus
-- Card fits into standard slot to connect to Apple II Internal
bus for Apple II standard I/O and control (Slot 3 reserved for
80 column capability)
| ProLine: bobl@pro-graphics
InterNet: crash!bobl@pro-graphics.cts.com | CServe: 70347,2344
ARPA/DDN: crash!pro-graphics!bobl@nosc.mil | AppleLink: Graphics3D
___________ ____________
Raven Enterprises - 25 Raven Ave. Piscataway, NJ 08854bobl@pro-graphics.cts.com (System Administrator) (08/27/89)
BUILDING YOUR OWN SCSI HARD DRIVE
By
Rick Hannon
When I first gave serious thought to building my own hard
drive I must admit I had some doubts. Let me rephrase that,
many doubts. Letting you in on my experience you will find
that its not that difficult and more cost effective than
buying an assembled drive.
My biggest fear was laying out $750 only to end up with a
bunch of used computer parts. This fear stayed with me
until the first time I booted up my machine with the hard
drive. I was also afraid that during the assembly I would
cross a wire or somehow damage the drive leaving me with a
repair bill before I even start. As you will soon see,
assembly is very easy and can be finished in under an hour.
The hard drive assembly I used was a Seagate ST277N which is
a 60 megabyte SCSI (Small Computer System Interface) drive.
The drive was ordered from Hard Drives International. The
external drive case was from Tulin Corp. and included
internal cabling and cooling fan. The external cable and
power cord were additional and were bought from Tulin also.
The Apple SCSI interface was bought from a local Apple
dealer. Other drives and cases are available from many
sources. Just browse through any issue of "Computer
Shopper" to find what is available.
Both orders were placed on a Tuesday afternoon and arrived
exactly seven days later. The hard disk was very well
packed with two-inch thick foam rubber surrounding the
drive. The drive is in a sealed plastic bag and placed
inside a smaller box. The external case was wrapped in
bubble wrap and placed in a box full of styrofoam peanuts.
You are bound to be excited to get started but please wait.
Ideally you should let your hard drive assembly stay sealed
in its plastic wrap for 24 hours to climatize to the
environment it will be used in. If you really can't wait
that long at least study the manuals included and take a
good look at the external case and parts involved. That
should take 8 to 12 hours... Right!
While we wait for the drive to climatize, lets take a look
at the external drive case from Tulin Corp. The case is all
metal construction measuring 4 1/4" high, 9 3/4" wide, and
10" deep. The finish is baked enamel in the Apple platinum
color. Two drives could easily be installed with just a
different internal cable and mounting bracket. The Seagate
ST277N needs a 13 watt power supply so the installed power
supply is large enough for two drives. Very nicely done
construction; however, the power switch is "cheap" and I
would prefer a toggle switch similar to the one on the back
of my computer.
Now that we have read the instruction manuals included and
the drive has climatized, lets begin by taking the following
precautions:
o DO NOT unwrap the drive until you are ready
to install it in the system.
o Always handle the drive by the frame or
casting.
o Do not touch the board components or
connectors without taking static-discharge
precautions.
DISK DRIVE ASSEMBLY
1. Remove the three flat head screws from the front panel.
Pull the front panel off the case being cautious not to pull
any wires that might be connected to the green LED on the
panel. If the wires are not already disconnected, do so
now.
2. Remove the black plastic switch extender (located on the
right over the power switch).
3. Slide the base plate assembly out though the BACK of the
case. (You might have to turn the base plate slightly to
get past the screw on the inner right side.)
4. The assembly instructions from Tulin showed how to wire
the LED to show disk access but with my ST277N I could not
do so because the drive didn't have a wire connecting to the
LED on the disk drive. Even if the drive had the wire, some
soldering would be necessary. Very few should be brave
enough to try this. Instead, mine shows power on only.
5. Open the wrapping from the drive assembly and carefully
remove. Remove the front black bezel from the drive by
removing the two brass screws holding it in place.
6. Locate the SCSI address jumpers on the drive assembly
and remove the jumper connected to pins. Attach the small
ribbon cable to the address jumpers. The red stripe on the
cable should be on your right when looking at the drive from
the rear. Do not use pressure.
7. Attach the 50-pin SCSI cable to the drive, again the red
stripe should be on the right when looking at the drive from
the rear. Be sure it is locked on tight.
8. Carefully place the hard disk onto the base assembly and
attach it with the four supplied screws. If you have
trouble aligning the drives assembly's holes to the base
plate, loosen the power supply's mounting screws to provide
some slack. Plug either one of the cables from the power
supply to the hard drive's circuit board.
9. Install the base plate/drive assembly into the case.
Attach the two thin wires (one colored, one black) from the
power supply to the LED on the front panel of the drive.
10. Attach the power cord to the rear of the case and turn
on the front panel power switch by sliding it to the right.
WARNING - DO NOT TOUCH ANY COMPONENTS WHILE THE DRIVE IS
PLUGGED IN!!! If the LED does not glow, turn off the power
and reverse the wires on the LED.
11. Re-attach the front panel assembly, being sure to mount
the black plastic switch extender properly on the switch.
Tighten the three screws until the back plate is in line
with the rear edge of the cover. Make sure the switch
extender moves freely.
o The decal to cover the screws cannot be removed
with damaging it. Do not affix until the drive
has been formatted and fully tested.
12. Open the top of your computer and install the Apple
SCSI Card (should be Revision C EPROM). Any questions
should be answered by reading the manual supplied with the
Apple SCSI Card.
13. Attach the DB-25 end of the external cable to the
connector on the computer and the other end to EITHER
connector on the rear of the drive case.
Now its fully assembled. That wasn't bad now was it. Now
the really time consuming part to the whole process.
Formatting and testing the drive. To do my formatting and
testing I used two "freeware" programs written by Joe
Jaworski. The programs are called "SCSI Hacker" and
"DiskTimer GS." These programs are available on AppleLink,
Compuserve, and GEnie. The programs come with very good
documentation, so I will only briefly cover them. My
instructions assume you have an Apple IIgs using GS/OS and
the Apple SCSI Card with Revision C EPROM.
FORMATTING AND TESTING
o Place the SCSI driver from the System Tools disk
into your /SYSTEM/DRIVERS folder on your System
Disk.
1. Boot up "SCSI Hacker" from your floppy drive.
2. Choose "Low level format" from the main menu. Choose an
interleave of five. Be patient, this might take a while.
3. Quit "SCSI Hacker" and now boot up "HDSCPartition" from
your "Apple SCSI Card Utilities Disk." It doesn't matter
how you set the partitions, as long as you set one for at
least 10 megabytes in size.
4. Now format your hard drive with your favorite utility
(Finder, Copy II Plus, Cat Doctor, System Utilities). This
should only take a few seconds.
5. Put a copy of "DiskTimer GS" on the new volume and
launch it from there. Wait until the tests have finished
and write the results down. Example:
Read = 93 Seek = 77 Adapter Speed = 51
6. Repeat the process again but this time use an interleave
of 10 (0A). Write down the test results of using the 10:1
interleave. Continue to increase the interleave by five
until you reach 20:1.
7. Compare the results of the read factor. For my drive
the best interleave was between 10:1 and 15:1. Example:
Interleave: 5(05) 10(0A) 15(0F)
Read Timing: 93 61 67
8. Now to pinpoint the best interleave I must begin the
format/testing process increasing the interleave factor by
one each time. To make a long story a little shorter the
best interleave factor was 10:1. You would think your
finished formatting now wouldn't you. The rule of thumb is
to increase the interleave by two to achieve the best
real-life performance. In my case a low-level format of
12:1 is the best to use. This gives me a "benchmark"
reading of:
Read = 63 Seek= 90 Adapter Speed = 51
All finished! Very easy to do but just a little time
consuming to get everything just right. Now we're ready to
install and configure software onto the hard drive itself.
Take your time! Backup your hard drive. Set-up
subdirectories (folders) to organize all your files. Backup
your hard drive. If you partition your drive its a good
idea to put applications on one and data on the other.
Backup your hard drive. It took every free minute of four
days to get all my files onto the drive, so be patient, and
backup your hard drive.
Those of you who haven't already, let me suggest you fork
out $40 to get ProSel by Glen Bredon. It gets its name from
the PROgram SELector that comes with the package but the
utilities included are more than worth the forty dollars.
You will wonder how you ever got along without it.
Utilities include a file handler, disk repair, disk zapper,
file de-fragmenter, file finder, fast disk copier, disk
backup/restore and more. For those who have an Apple IIgs,
get ProSel 16! Available February 1, 1989 for just $60.
You cannot get ProSel or ProSel 16 from your local retailer.
Only from Dr. Bredon himself. Send your check to:
Glen Bredon
521 State Rd.
Princeton, NJ 08540
COST BREAKDOWN
Seagate ST277N ...........................$449.00
Tulin Corp. Case w 30w power supply
and internal cabling .....................$119.00
Power cable ..............................$ 4.00
External cable ...........................$ 25.00
Apple SCSI Card w Revision C .............$129.00
---------
$726.00
o Shipping/handling, sales tax, and possible COD or
credit card surcharges not included.
SEAGATE SCSI DRIVE SPECIFICATIONS
ST225N ST251N ST277N
------ ------ ------
Formatted Capacity 21.4 42.8 64.9
Number of Disks 2 3 3
Number of Heads 4 6 6
Avg. Access Time(ms) 65 40 40
Avg. Power Consumption 16.8 13 13
Auto Head Park @
Power Down NO YES YES
Ballpark Price $299 $395 $449
All three use sputtered, thin film media and should operate
at temperatures of 50 to 113 degrees.
POSSIBLE MAIL ORDER SUPPLIERS
Hard Drives International
1208 E. Broadway Rd. #110
Tempe, AZ 85282
Orders: (800) 234-DISK
(602) 784-1038
Customer Service: (800) 541-8387
Order Status: (800) 541-8387
Telex: 405765
Fax: (602) 829-9193
(Hard drives)
Tulin Corp.
2393 Qume Drive
San Jose, CA 95131
(408) 432-9025
Telex: 499-4365
Fax: (408) 943-0782
(External cases, cables, &
complete hard drive kits)
IB Computers
1519 S.W. Marlow
Portland, OR 97225
(503) 297-8425
(External cases)
Lyco Computer
(800) 233-8760
(Hard drives)
jb Technologies, Inc.
21011 Itasca St. #F
Chatsworth, CA 91311
(818) 709-6400
Telex: 678953
Fax: (818) 341-2935
(Hard drives)
ComputAbility
P.O. Box 17882
Milwaukee, WI 53217
(800) 558-0003
Fax: (414) 357-7814
(Hard drives)
CTI Continental Trading, Inc.
(800) 284-8494
(Hard drives)
I don't claim to be an expert but I'm always willing to help
others who wish to try assembling their own hard drive. You
may reach me through the following information services.
AppleLink: RHannon
GEnie: R.HANNON
Compuserve: 75530,3136
============================================================
A D D E N D U M
============================================================
THIS PORTION PRIMARILY CONCERNS USERS OF HARD DRIVES OVER
40-MEGABYTES IN SIZE WHO USE THE GS/OS OPERATING SYSTEM.
Interleave
----------
Shortly after uploading this to the information services it
was brought to my attention by Bob Consorti and Glen Bredon
that DiskTimer GS gave an incorrect "Read" test with GS/OS.
Previous operating systems didn't use multiple block reads
and DiskTimer GS doesn't test for this improved method.
To perform an accurate "Read" test you must copy the system
disk files, and several GS specific programs (AppleWorks GS,
MultiScribe GS, Paintworks Plus, etc.) to the hard drive
instead of DiskTimer GS. Use a stop watch or any watch with
a second hand and time cold bootup and launching of the
various programs, recording the results as you go along.
Repeat the process with different interleave factors until
you find the one which gives the best results. You have now
found the correct interleave.
Volume Partitioning
-------------------
There seems to be another problem with volumes over
40-Megabytes in size when using the Advanced Disk Utility
(ADU). I'm not an expert and my explanation of the problem
may not be totally correct but my instructions to clear-up
the problem are.
SCSI devices are intelligent devices. When the low-level
format takes place the drive assigns all bad blocks to the
end of the drive.
"Advanced Disk Utility" will allow you to set the partitions
over this bad block area. This results in a corrupted
volume bit-map. If you don't believe me, set your
partitions to use 100% of the drive then use "SCSI Hacker"
to test the last partition on the drive. You should get an
error #27 (I/O Error) soon as the test starts.
To allow for the bad block area, set 1% of the hard drive as
unused. On the Seagate ST277N, ADU leaves 512K as unused
disk space. On my hard drive the partitions are as follows:
/HD1 = 50% /HD2 = 49% Unused = 1%
You probably only have about 100K of disk space that is
actually bad but one percent is the smallest amount of space
ADU will allow you to partition as unused.
As a safeguard I would recommend that you again use "SCSI
Hacker" to test the final partition again. This time you
should not get the I/O error and the program will allow the
test to continue. If it doesn't then you have more than
512K of bad blocks. You will then have to leave an
additional one percent as usused. If this is a new drive
assembly I would also recommend that you get in touch with
the firm you bought the drive from and ask for a
replacement.
This file was updated on February 23, 1989.
| ProLine: bobl@pro-graphics
InterNet: crash!bobl@pro-graphics.cts.com | CServe: 70347,2344
ARPA/DDN: crash!pro-graphics!bobl@nosc.mil | AppleLink: Graphics3D
___________ ____________
Raven Enterprises - 25 Raven Ave. Piscataway, NJ 08854jason@madnix.UUCP (Jason Blochowiak) (09/01/89)
I found that not knowing when my //gs was accessing the hard drive was annoying, so I found an easy and cheap way to take care of it. It's been awhile, but here are the basics: 1) Remove the black cover plate from the 277N with a screwdriver 2) Remove the little metal thingies from one end of the wires that lead from the AHive's access LED to where the access LED hookup would be on a different drive. (Ok, that was incoherent - it's 7:05am, and I'll be going to bed soon...) Put another way: There is a pair of wires twisted together (they come with the AHive). On both ends of each of these wires, there are "female" metal things that slip over the prongs that come out of the LED (on one end of the wires) and the prongs that I guess are one other drives. So, we need the thingies on one end of the wires (to hook up to the green access LED in the AHive), and we need the other end to be bare wire. 3) Insert the bare wire ends into the thingies that you bought from Radio Shack. The thingies required from RS are small plastic deals that have a place to stick a wire into on one end, and have a small (~1mm) metal hook that extends from the plastic body when you push. They're used (by normal folks), I imagine, for "lifting" a signal from a pair of wires. 4) Look into the front of the 277N where the green LED is - you should be able to see the wires that are connected to it. Hook the metal part of the plastic RS thingies onto the wires, one on each side. Make sure that the metal parts don't touch anything inside the drive except the LED wires. You should now have a 277N with two wires sticking out the front, with metal thingies to attach to a LED. 5) Attach the metal LED attaching thingies to the green access LED that's part of the front of the AHive. Voila! You're done... Of course, I've skipped some stuff like disassembling the drive, making sure you don't fry it or yourself, making sure that the polarity is correct for the LED, and re-assembling the drive without pulling the wires off. I know this works, as my drive is set up like this, and the access light works... No soldering (aside: Anyone care to email me as to why this word is pronounced "sotter"?) required, and the whole thing is removeable (just unclip the plastic thingies from the drive). Btw, the LED actually attached to the 277N still operates. If you do this, you are doing it at your own risk. If you proceed with this, and you're even more of an electronics novice than I am (ha! take a look at the part descriptions I gave!), you might want to get some help from someone who knows enough to decipher what I've written. If someone out in netland knows the specific names for what I'm talking about above (write to me if you think you know, but aren't sure) and is capable of writing a decent description, please do re-write this. -- --------8<------------------------------------------------------------8<-------- jason@madnix.UUCP "I am opposed 180 degrees" - George Bush, master mixer of metaphors. (Is the IInix mailing group still out there?)
jason@madnix.UUCP (Jason Blochowiak) (09/01/89)
First off, it seems like the CMS card is pretty much of a pain - I didn't have to play around with setting jumpers with the Apple card. Mostly personal preference here, though... Although a very nice article, it seems we once again have the "interface" vs. "storage method" confusion. SCSI or ST-506 (I'm sure there are others) are defined methods for the computer to talk to the hard drive (or vice-versa). MFM (Modified Frequency something-or-another. I think the s-o-a is Modulation) and RLL (Run-Length Limited) are ways that the drive itself uses to store information on the physical drive media. The only thing that you have to worry about (with an Apple //) is that the drive can use SCSI - some drives (like the SeaGate ST-xxxN that the author talks about) can understand SCSI without any modification or enhancements. If a drive doesn't understand SCSI by itself, you have to stick a controller card on it, as mentioned. This is when you have to start worrying about whether or not the drive is MFM or RLL. If a controller card thinks that it's talking to an RLL drive when it's not really, some problems could come up later on (as RLL requires better media). So, if you go the controller & ST-506 mechanism way, make sure that the controller and the mechanism (the actual drive) are in agreement on what storage format is being used. My personal observations regarding how much storage you need: Take your original estimate, and multiply it by two. Even after you've adjusted to (and hopefully cured) harddriveitis (a horrible condition, symptoms of which include sticking everything you see on your hard drive. There are related diseases, such as i'llkeepthat'causei'llwantitlateritis, but that's too horrible to talk about in mixed company), you'll probably find that what you once considered to be "Soooooo much storage" is getting a bit cramped. I personally have rather large requirements, what with some three entirely different development systems sitting on my hard drive, lots of text files, pictures, and their ilk, and FreeWare and ShareWare (even if I don't use the stuff) all over the place. This is in addition to that ever- growing chunk of system software coming from Apple ;) The "incredible shrinking storage space" syndrome is similar to that of the "increasingly small amount of memory I have in my system" syndrome. When I first got my //gs, I thought that, because I was buying a megabyte (the maximum I could get without going 3rd party), I would be set for quite awhile, and I wouldn't have to buy any more for a long time. Well, at the moment I'm looking into picking up a few more megs (especially considering that the prices are pretty cheap right now). -- --------8<------------------------------------------------------------8<-------- jason@madnix.UUCP "I am opposed 180 degrees" - George Bush, master mixer of metaphors. (Is the IInix mailing group still out there?)