Tandy Professional Forum   Section: T1000/1400/3000/4K
Subject: Tandy 4000 hard drive   Total messages: 11
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#62702   2 Replies   12/07/96   10:12:06
From: Fred Berney, 71020,1207
To:   ALL

The hard drive on my Tandy 4000 bit the dust. It is a Seagate
ST120. I tried to replace it with another Seagate 120 Meg hard
drive that I from another computer.

Actually, my brother is attempting this and he lives 1200 miles
away, so I did not actually see the connections myself, but he
tells me that the connection on the original Seagate is different
from the newer drive that I sent to him.

From his description, it sounds like there is a driver actually
attached to the hard drive that is now in the 4000.

Does anyone know if it is possible to use a different drive in
the 4000? If so, what needs to be done.

If the same drive that is in there now must be used, does anyone
have a used working drive they are looking to sell?

                              Fred


#62704   Reply to #62702   2 Replies   12/08/96   08:01:23
From: F. Barry Mulligan, 70035,140
To:   Fred Berney, 71020,1207

Fred,

    As far as I can find, Seagate never made an ST120 (it would have been
a 3.5-inch 41mm height MFM with 20-meg unformatted capacity, following
Seagate's standard model designations). They did have an ST3120a (3.5-inch
25mm with 107 meg) with a 16-bit IDE interface.

    The original T-4000s usually came with a 40-meg MFM drive, either from
Microscience or CDC. These used an ST-506/412 interface, the earliest hard
disk standard.

    Before you try to plug a drive into the machine, find out what controller
& interface it uses. The T-4000 did not have a built-in interface, so no
matter what type of drive there will be a board in one of the slots. It might
be:
    ST-506/412 (MFM or RLL) - with the controller on the board;
    IDE (XT type) - an 8-bit interface, with controller on the drive;
    IDE (AT type) - a 16-bit interface,   "      "      "   "    "
    ESDI
    SCSI
Check the markings on the board to determine the type, then install a
compatible drive. The drive itself should have its specifications, or at
least the correct model number, printed on it. The last character of the
Seagate number indicates the type (none - MFM; R - RLL; X - 8-bit IDE;
A - AT IDE; E - ESDI; N - SCSI).

    If you want to change the drive type, you'll have to change the
interface / controller to match.

                                                       /* barry /&


#62705   Reply to #62704   2 Replies   12/08/96   11:56:20
From: Fred Berney, 71020,1207
To:   F. Barry Mulligan, 70035,140

Barry,

My brother has the computer and he read the model number to me
over the phone. I could have made a mistake in copying the
number.

I do know that the drive is a 40 meg. He did say the manufacturer
was Seagate, and I seem to remember that was who made the drive.
(This was one of my old computers that I gave to my bother)

From his description, it sounds like there is a controller board
attached to the hard drive. Is this possible?

He said that the connectors that go from the mother board to the
hard drive are different than the connection on the Seagate drive
that I sent to him. Without seeing the old drive, but only from
his description, it sounds like the cable runs from the computer
into some kind of board attached to the drive and then the board
is connected, somehow, to the hard drive.

He was not able to tell me if there was a cable running from the
board to the drive.

Does any of that make sense?

Let's say we scrape everything and try to attach this 120 meg
drive that I sent to him to the computer. If I just bought an IDE
controller, that plugs into one of the ISA slots, would that
work?

                                    Fred


#62710   Reply to #62705   12/09/96   06:54:07
From: F. Barry Mulligan, 70035,140
To:   Fred Berney, 71020,1207

Fred,

    Any type of hard disk will have some electronics mounted on it, so the
description of "some kind of board attached to the drive" doesn't provide
much help. Since the T4000 did not have an interface or controller built
into the motherboard, there would also have to be a board plugged into one
of the motherboard slots, with one or more ribbon cables running to the
drive (plus the cord from the power supply). Without knowing the type of
drive, it's not possible to know what you had.

    If the replacement drive is an IDE type, you could buy an IDE interface
card, plug it into the motherboard, and connect it to the drive (note that
this is an _interface_ card - the actual controller is on the drive). You
still have to determine if you have an XT-style IDE drive (8-bit) or an
AT-style (16-bit), and purchase the appropriate interface card.

    It's possible that both the original and replacement drives are IDE, but
different styles (XT vs AT). I'd suggest you get positive descriptions
(manufacturer's model nbrs or detailed specs) of both drives, plus the card
plugged into the motherboard, before going any further.

                                                          /* barry /&


#62711   Reply to #62705   1 Reply   12/09/96   11:55:16
From: Robert A. Hengstebeck, 76417,2751
To:   Fred Berney, 71020,1207

To add to what Barry Mulligan said to you, you can get the ide
controller board from Radio Shack for around $29.00.  Ask for
part number (guessing now) 25-1098.


#62716   Reply to #62704   1 Reply   12/11/96   00:51:22
From: Fred Berney, 71020,1207
To:   F. Barry Mulligan, 70035,140

Barry,

My mistake about the part number. I just double checked the
numbers and the original drive is a Seagate ST251.

The drive I am trying to install is a Seagate ST3144A.

So, if I understand your message, the ST251 is a MFM drive with
the controller on the board.

I know the ST3144A is an IDE drive, since it came out of an Amiga
computer. I'm not sure if it is 8 or 16 bit. Maybe you can help
there.

Since I am changing the type of drive, I need to get a new
interface/controller to match.

Will this controller plug into one of the ISA slots on the
computer or need to go onto the mother board? Without being able
to see the computer, I don't know if the current controller is
soldered or plugged into the Tandy mother board.

Also, the original drive was a 5 1/4" drive, and the drive that I
am now trying to use is a 3 1/2" drive. Is that a problem? My
brother says there is lots of room for it to sit. Do I need some
kind of a mounting kit for a 3 1/2" drive or just screw it in the
best we can?

I really appreciate your help on this. Thanks.

                        Fred


#62717   Reply to #62711   1 Reply   12/11/96   00:51:23
From: Fred Berney, 71020,1207
To:   Robert A. Hengstebeck, 76417,2751

>>>To add to what Barry Mulligan said to you, you can get the ide
controller board from Radio Shack for around $29.00.  Ask for
part number (guessing now) 25-1098.>>>

Robert,

Would this IDE controller board replace the board that is not in
the 4000? Is it a plug in type board? (not solder)

Thanks.

                              Fred


#62719   Reply to #62717   12/11/96   12:17:11
From: Robert A. Hengstebeck, 76417,2751
To:   Fred Berney, 71020,1207

This is a plug in board.  Another option, is to buy the super ide
IO boards, that allow you to hang 4 ide hard drives, or 2 ide
hard drives and a ide type CD-ROM in the computer.  The super ide
IO board is explicitly designed to handle the new super hard
drives that are currently on the market.


#62720   Reply to #62716   12/11/96   18:03:07
From: F. Barry Mulligan, 70035,140
To:   Fred Berney, 71020,1207

Fred,

    Unless you're a technician, there are only two occasions when you would
take a soldering iron to a computer: 1) If something is broken, or 2) You are
about to break something <g>.

    The ST251 that you are removing is, in fact, a 43MB MFM drive with a
5.25" half-height form factor. It's controller is on a separate board that
plugs into one of the standard slots in the motherboard. The ST3144A is a
130MB IDE (AT style, i.e. 16-bit) with 3.5" 1/3 height form factor.

    An IDE drive has its controller on the drive. This connects to the
computer's IDE interface. Since the T4000 has no built-in IDE interface,
you will need an IDE-AT adapter board, which plugs in the same way the
MFM controller did. Tandy's catalog nbr was 25-4121 (#25-1088 was the 8-bit
i.e. XT style adapter), but you probably can buy one from any decent
computer store.

    Beyond the interface board, you still have two problems. The replacement
drive is smaller in all dimensions and the existing mounting won't hold it.
There are adapter kits available from computer stores that will probably
have the necessary hardware for the mounting, but you (or your brother) will
have to find a clerk who knows what he's selling.

    A possible second problem is the old controller board, which may also
support the floppy disk drives. The T4000 came with a built-in floppy
controller that was usually disabled if a dual (hard/floppy) controller
board was installed. If your brother finds the floppys connected to the
motherboard, he's cool. If there's a cable from the plug-in controller board
to the floppys, check back for instructions on reconnecting them to the
motherboard.
                                                     /* barry /&


#62721   Reply to #62702   1 Reply   12/11/96   22:18:14
From: Timothy G. Loiselle, 103000,1732
To:   Fred Berney, 71020,1207

Fred
  Install a Gsi model 18 ide controller and change your setup to
no harddrives  attached. The controler has an onboard bios that
will auto detect any ide drive.All you have to do is fdisk and
format the drive and you will be okay.  I used this card with the
same drive and it worked fine.  This card is also a data
accelerator card and transfer is about 25% faster.  The floppy
drive jumpers are  E5, E6 and E7.  E5 & E6 should be jumpered to
make the on board controller primary.  Jumper E6 & E7 to use
another floppy controller. If you need any more  jumper settings
let me know as I have a manual. GOOD LUCK!!
     Tim


#62723   Reply to #62721   12/12/96   19:03:29
From: Fred Berney, 71020,1207
To:   Timothy G. Loiselle, 103000,1732

Tim,

Thank you. I'll let you know how it turns out or if I need help.


                           Fred


