Dec 092017
Installing that 2nd hard disk.
File 2NDHRDSK.ZIP from The Programmer’s Corner in
Category HD Utilities
Installing that 2nd hard disk.
File Name File Size Zip Size Zip Type
2NDHRDSK.TXT 18816 6817 deflated
TPCREAD.ME 199 165 deflated

Download File 2NDHRDSK.ZIP Here

Contents of the 2NDHRDSK.TXT file

#: 195700 S0/General/New Uploads
09-Dec-85 01:30:02
Sb: #2 Hard Disks
Fm: John MacVeigh 72467,2141
To: James Bach 76555,273 (X)

James, About two weeks ago you replied to a question I had about
adding a second full-height hard disk to an XT. I've had to post-
pone the installation, and now I have a second question... How do
you power your three drives ? My XT has only 2 power lines for disks.
Did you get another power supply, or was one of the two tapped into?
Thanks again, John

#: 196102 S0/General/New Uploads
10-Dec-85 00:55:08
Sb: #195700-#2 Hard Disks
Fm: Joan Friedman 76556,3643
To: John MacVeigh 72467,2141 (X)

John, all you need are little Y-connectors for the cables coming from your
power supply (these are the four-line cables with red, green, yellow, and black
wires). The Y-connectors are available from a number of places that advertise
in Computer Shopper, and cost, as I recall, about $1.20 each. My upgraded
power supply (I only had a regular PC to start with) came with these connectors
already installed, so I know they work. ---Joan

#: 195701 S0/General/New Uploads
09-Dec-85 01:37:47
Sb: #2 Hard Disks
Fm: John MacVeigh 72467,2141
To: John McHugh 75365,331

John, About two weeks ago you replied to a question I had about
adding a second hard disk to an XT. I've had to postpone the
installation, and now I have another question. You mentioned insuring
that only the second (last) drive have a resistor terminating pack.
The question is: Where is that pack? A quick look at the drive didn't
turn up anything that look unpluggable, and the XT Tech Ref manual I
have didn't seem to say anything about it. Since my current C: drive
must have one already, I just want to be able to check the new drive
for one. Thanks a lot! -- John

#: 195739 S0/General/New Uploads
09-Dec-85 08:08:47
Sb: #195701-#2 Hard Disks
Fm: Stephen Satchell 72736,70
To: John MacVeigh 72467,2141

There are three configurations for the terminating resistors. First, there will
be what looks like an IC but different in color (most of them I've seen have
been blue) with a strange number on top. This will physically appear near the
connectors. The second configuration is a very small bar with wires coming out
the bottom. Close examination of the foil side of the circuit card will show
that instead of being soldered in, there are very small sockets (press-fit) in
the board, into which said bar is plugged in. The last configuration is that
the resistors are soldered in, but there is a switch that will logically
disconnect the resistors.

If you have ANY drive documentation (you can request it, perhaps for a small
price) there should be a diagram pointing out exactly where the terminating
resistors are. Failing that, there should be a paragraph explaining how to yank

Several folks here have reported NOT removing the resistors and running just
swell. I don't recommend the practice, but if you can't find the bugger, then
try it (of course, back EVERYTHING up from the existing drive).

#: 195760 S0/General/New Uploads
09-Dec-85 09:32:55
Sb: #195739-#2 Hard Disks
Fm: Basil Copeland 71656,472
To: Stephen Satchell 72736,70 (X)

Started following this thread because I will be adding a 2nd hd soon.
Are you saying there are terminating resistors on hd's also? I knew there
were on floppys. Also, do you happen to know what kind of cable it takes to
daisy chain two hd's? My understanding is that the cable used for floppys in
the pc has a "twist-in-the-cable" to enable drive select rather than using the
jumpers on board the drives.
Would this be true also for hard drives? Thanks if you can help (and thanks
for trying if you can't). --Basil

#: 195869 S0/General/New Uploads
09-Dec-85 17:07:01
Sb: #195760-#2 Hard Disks
Fm: Stephen Satchell 72736,70
To: Basil Copeland 71656,472 (X)

The A-cable is similar, with the cut and twist in the cable. On HDs, there is
also a separate data cable (the B cable) which is balanced data (the data rates
are too high to be carried on the one cable, unlike floppys; HDs go 5 MHz
whereas floppies are around 250K-500KHz).

The drive has to respond to drive select 2 on the AT (and I suspect on the XT
as well).

#: 195919 S0/General/New Uploads
09-Dec-85 18:42:25
Sb: #195869-#2 Hard Disks
Fm: Basil Copeland 71656,472
To: Stephen Satchell 72736,70 (X)

Thanks for the answer. H"think I understand, although I am not familiar with
the "A" and "B" cable convention. Would I be right in assuming that the "A"
cable is a 34 pin daisy chain cable, and the "B" cable is a straight 20 pin
cable? I think my controller card has two 20 pin connectors, and one 34 pin
connector. I would then connect the center connector on the daisy chain to my
first hard drive (C:), and the end to the second (D:). The 20 pin cable would
run from D: to the empty 20 pin connector on the controller board. I asked
about the twist in the cable because I have some cables left over from
installing teacs on sanyos that don't have the twist, and depend upon a jumper
on the drive to select the right drive. Well, I think I got it now...its just
a question of finding a local supplier who has the cables. Again, thanks.

#: 195998 S0/General/New Uploads
09-Dec-85 22:06:34
Sb: #195919-2 Hard Disks
Fm: Stephen Satchell 72736,70
To: Basil Copeland 71656,472

Actually, if you use the IBM cable, the A cable goes to D FIRST (if you have
two disks) THEN to C. If you don't have the twist, try setting your drive C to
2 and drive D to 3. AND don't forget to find and remove the terminating
resistors from the D drive...

#: 196105 S0/General/New Uploads
10-Dec-85 00:56:06
Sb: #195869-2 Hard Disks
Fm: Joan Friedman 76556,3643
To: Stephen Satchell 72736,70 (X)

Steve, whether there is a twist in the 34-pin communications cable is not
standard, the way it is for floppies: it depends on the controller. My Xebec
does *not* use a twist in the cable. ---Joan

#: 196163 S0/General/New Uploads
10-Dec-85 02:39:55
Sb: #195739-2 Hard Disks
Fm: John MacVeigh 72467,2141
To: Stephen Satchell 72736,70 (X)

Steve, Thanks for the descriptions. I'm familiar with the "bar and plug" set
up, but I didn't know that's what those blue "IC"s were. I'll check again,
maybe the pack has already been removed. -- John

#: 196169 S0/General/New Uploads
10-Dec-85 03:55:13
Sb: #196103-2 Hard Disks
Fm: JAMES BACH 76555,273
To: Joan Friedman 76556,3643

I left out a (possibly) crucial detail re: my setup. The guy who set me up
yanked out the floppy drive, placed the second hard disk in its place, and
placed the floppy drive in a little box external to the rest of the stuff with
a flat, blue cable threaded through a slot where a port could be. Does this
explain anything vis a vis the power supply arrangement? And, how is it
possible for the two hard drives to NOT be on a y extension? Intuitively, one
would conclude that the two are set up sequentially. Is this possible?!

#: 196202 S0/General/New Uploads
10-Dec-85 08:14:26
Sb: #196169-#2 Hard Disks
Fm: Joan Friedman 76556,3643
To: JAMES BACH 76555,273 (X)

If your floppy is now in an external box, the usual arrangement is that there
is an auxiliary power supply in the box that powers the drive there. Is that
not the case? If not, you would need somehow to route a power line to it. But
if it is the case, then there is no problem, since you can use the original two
power lines for the two hard drives. The flat blue cable you see is the data
cable, not a power cable.

Two types of cables go to a hard drive in addition to the power lines. The
20-pin data cable is drive specific: each drive has its own cable that connects
to a unique connector on the controller. There is only one 34-pin
communications cable, which goes sequentially from one drive to the next. In
some setups (depending, I think, on the type of controller), there is a twist
in this cable, similar to the one you find in twin-floppy setups; but in other
circumstances (mine, for example), the twist is not needed. The determination
of which drive is which is done via the data cables and dip switch settings on
the drive.

Why don't you open up your box and see how it's set up? I'd be interested in
hearing the result. ---Joan

#: 196220 S0/General/New Uploads
10-Dec-85 09:19:50
Sb: #196105-#2 Hard Disks
Fm: Basil Copeland 71656,472
To: Joan Friedman 76556,3643

Oh geez, Joan...just when I was getting my nerve up about adding a second hard
drive, and you gotta drop that one on me. I got my first hd from your friends
at 47th street, and was so pleased with the instructions and installation that
I ordered a second one. I haven't got it yet, but the instructions with the
first covered the installation of a second. With respect to cables, the
instructions just say that I need a 34 pin daisy chain cable. Thus the
dilemma: is that a cable with a twist in it or not? The instructions don't
say. The controller card is a western digital. Why doncha go back to sunny
california . At least you wouldn't be around for me to blame if anything
goes wrong. --Basil

#: 196249 S0/General/New Uploads
10-Dec-85 09:57:12
Sb: #196220-#2 Hard Disks
Fm: Conrad Kageyama (Sysop) 76703,1010
To: Basil Copeland 71656,472 (X)

Basil... Joan has the "twist in the cable" a little confused, so let me
clarify... A "twist" in the cable simply allows the drives to be configured
the same (C or D), i.e., the twist handles the drive designator switches.. When
there is no twist in the cable, then the switches on the drive MUST be
configured as first or second drive... Most after-market cables are NOT
twisted, ergo, the drive switches MUST be configured... connie

P.S. did I say it right, or are you now more confused???

#: 196282 S0/General/New Uploads
10-Dec-85 11:17:47
Sb: #196249-#2 Hard Disks
Fm: Basil Copeland 71656,472
To: Conrad Kageyama (Sysop) 76703,1010 (X)

Connie...I think you made it *more* clear. I think the installation
instructions that come with the 47th st 20 mb disk assume that the cable does
*not* have the twist since they provide explicit instructions on configuring
the disk drive dip switches. In other words, I am assuming that drive select
is handled via drive configuration rather than the twist in the cable. Does
that sound right? --Basil

#: 196313 S0/General/New Uploads
10-Dec-85 11:52:58
Sb: #196282-2 Hard Disks
Fm: Conrad Kageyama (Sysop) 76703,1010
To: Basil Copeland 71656,472 (X)

yes, you got it... I think that IBM is the only one that supplies a twisted
cable so that they can stock only one configuration of hd... On anything with
a straight cable, you MUST be sure to have the drive configuration switches set
properly... connie

#: 196405 S0/General/New Uploads
10-Dec-85 17:46:45
Sb: #196313-#2 Hard Disks
Fm: Basil Copeland 71656,472
To: Conrad Kageyama (Sysop) 76703,1010 (X)

I got it, huh??? Since this am, ups dropped a shipment from 47th street on my
doorstep: my new hard drive, and some software. first pass at
installing the 2nd hd was a bust. Right now, only two possible problems come
to mind: the configuration switches, and the terminating resistor. I did not
remove the terminating resister, because I was following instructions "by the
book" and there was no instruction to remove one. I have looked around, and
can not even see one in a readily accessible location. What should I be
looking for (I know "what"--I mean "where")? Also, my instructions say to
connect the end of the daisy chain to drive D:, and the center to drive C:.
Does that make sense? Any help will be appreciated.
So far, no major harm has been done...I reinstalled drive C: without a hitch.

#: 196410 S0/General/New Uploads
10-Dec-85 18:01:58
Sb: #196313-#2 Hard Disks
Fm: Basil Copeland 71656,472
To: Conrad Kageyama (Sysop) 76703,1010 (X)

I got the second drive installed and formatted, only to realize that it was a
10 mb drive!!!! That's right folks, 47th street shipped me a 10 mb drive in a
20 mb drive box!!! Charged me for a 20 mb drive, of course. It's too late in
the day now to get through to their customer service. It'll be interesting to
see how they handle this when I call them tomorrow. --Basil

#: 196460 S0/General/New Uploads
10-Dec-85 18:56:41
Sb: #196405-2 Hard Disks
Fm: Conrad Kageyama (Sysop) 76703,1010
To: Basil Copeland 71656,472 (X)

Generally speaking, the drive at the end of the cable should have the
terminating resistor... However, after much research into this matter, having
talked to, among others, MicroScience and Tandon, it seems that a system will
work 90% of the time with both resistors in place, though it does strain the
driver chips... If you tell us what brand drive you have, then perhaps one of
our members can tell you...

As far as being a "bust" goes, what happened when you tried to access the
drive??? Remember that you must set the drive configuration switch on the
drive to identify it as the first or second hd, and you must also set the
switches on the controller board to tell it that you do in fact have two
drives. Then the cabling of course, and finally a FDISK and FORMAT. What kind
of errors are you receiving???... connie

#: 196464 S0/General/New Uploads
10-Dec-85 19:05:53
Sb: #196410-#2 Hard Disks
Fm: Conrad Kageyama (Sysop) 76703,1010
To: Basil Copeland 71656,472 (X)

WAIT!!!!... Are you sure that it's a 10megger and that you're controller board
is just not mis-configured for a 10megger??? One of our other members ran into
this problem... connie

#: 196508 S0/General/New Uploads
10-Dec-85 20:33:19
Sb: #196464-2 Hard Disks
Fm: Basil Copeland 71656,472
To: Conrad Kageyama (Sysop) 76703,1010

Well...I will know more when I call tomorrow. The drive came in a box that
said "EZ-20" on the outside. The disk itself said "EZ-510." It's supposed to
be a Microscience drive, for all that's worth. The new drive came with an
adaptec controller board, and related installation instructions. I have a
western digital controller board running my current 20 mb hd. I tried setting
the dip switches up the way the western digital docs said, and that didn't
work. Drive C: wouldn't even boot. So I set the dip switches according to the
adaptec doc. Drive C: booted, I did the primary format per the western digital
docs, and fdisk/format only gave me 10 mb. As for reconfiguring the dip
switches, I don't have anything else to go on, so I don't know if that's the
problem. What is curious is that I can't tell from the installation
instructions whether they relate to a 20 mb drive or a 10mb drive. They are
not nearly as well-done as those that came with the last drive I got from 47th
st. --Basil

#: 196581 S0/General/New Uploads
10-Dec-85 22:29:53
Sb: #196464-2 Hard Disks
Fm: Basil Copeland 71656,472
To: Conrad Kageyama (Sysop) 76703,1010 (X)

Connie...after your last message, I decided to experiment a little further. I
decided that if the drive was simply configured wrong, it ought to be simple
enough to substitute it for my current 20mb C: drive and configure it
accordingly. GUESS WHAT HAPPENED??? It formatted out to 20 mb!!! So it WAS a
configuration problem. I still had trouble getting the two to work together as
C: and D: until I realized that the dip switch illustration in the docs that
came with the wd controller showed on as up, and off as down. That's
BACKWARDS. Besides, the settings were off. What were perfectly good
instructions for installing a single "preconfigured" drive were totally
unreliable for installing two drives. In this case, the dip switch settings in
the adaptec instructions were more accurate.
Anyway...I've got a D: drive now that formats out to 20 mb. It is formatted
as a "system" disk, but I don't see what harm that will do, and if I need to, I
can always remove the system files. But for now, everything seems ok. Thanks
for the help. It's great to have you guys (and gal(s)) around to help get
through these problems. --Basil

#: 196589 S0/General/New Uploads
10-Dec-85 22:43:41
Sb: #196508-2 Hard Disks
Fm: Conrad Kageyama (Sysop) 76703,1010
To: Basil Copeland 71656,472 (X)

I think I can answer your questions now... First off, if you also got another
controller, specifically, the Adaptec, then the instructions using THAT
controller need not be as clear as that controller is supposed to be "smart" in
that it reads ANY drive and writes a configuration drive to the disk when first
booted... Thereafter, each time the machine is booted, it just reads that
file, configures itself, and you're off to the races...

As for the WD, it is more conventional in that the drive select switches on the
drive must be correct (first and second drive) (MicroSci uses switches), AND
the jumpers on the WD must be properly set according to the on-board ROM
specifications... The on-board ROM must contain a table for your particular
type of drive (head and cylinder configuration), or it won't work...

BTW, which board do you plan to use??? Keep in mind that if you use the
Adaptec, then you will have probably have to reformat your old drive too. If
you decide to use the WD controller, then you will have to call 47th St and
find out the jumper selections on the WD for the second drive... connie

#: 196819 S0/General/New Uploads
11-Dec-85 12:35:24
Sb: #196589-#2 Hard Disks
Fm: Dave Hoagland 72365,42
To: Conrad Kageyama (Sysop) 76703,1010 (X)

Connie- Have you used the Adaptec? I'm curious...I assume the configuration
file is pretty well hidden. It would be interesting to do a complete backup
from one drive, swap drives (replace it with a different type, same capacity)
and restore to the new drive. If the configuration file was transferred from
the first drive to the second...
I realize that this sounds pretty unlikely, except that I end up playing
this juggling act on a semi-regular basis in the process of evaluating HD's.
Surely they have *some* technique of verifying the validity of the
configuration file...or possibly it's an absolute location arrangement?
If they have a technique of avoiding this potential problem, it sounds
like something that I could use... ...DaveH

 December 9, 2017  Add comments

Leave a Reply