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Bungo Pony
August 28th, 2013, 08:43 AM
I've got a dead Olivetti sitting here, but I moved the hard drive and controller card into my no-name PC-XT, and it works fine. I'm wondering if it's possible to put two hard drives in this thing. I'm guessing it would be some sort of addressing issue that would need to be resolved, and I have no clue if it's at all possible.

Stone
August 28th, 2013, 09:04 AM
Just plug'em in and goforit. Doesn't your controller support two hard drives? If not, use one that does.

pearce_jj
August 28th, 2013, 09:34 AM
Addressing is controlled by the flipped wires in the ribbon cable - not sure about termination mind.

Bungo Pony
August 28th, 2013, 09:34 AM
Both of the controllers have one 34-pin connector and two 20-pin connectors which go to the hard drive. Does the 34-pin one need to be in parallel?

Also, I've had previous difficulty with matching up a hard drive with an oddball controller card, and needed to do a low level format to make it compatible. I'm guessing that may end up being the case again.

Agent Orange
August 28th, 2013, 09:49 AM
All of the above. If all else fails, some early XT clones required MS-DOS's DRIVPARM in order to access an additional HDs.

Chuck(G)
August 28th, 2013, 09:55 AM
If you can't find a proper 34-pin cable with a "twist" in it (not the same as a floppy cable twist), just use a "flat" cable and set one drive to DS0 and the other to DS1 via their jumpers--and only the last drive on the cable should have its terminator installed. One 20-pin cable per drive.

Stone
August 28th, 2013, 10:07 AM
Or you can add the twist yourself. Or you can remove the twist from a floppy ribbon cable and add the correct twist yourself. Or I could send you a dual hard drive ribbon cable and one additional data ribbon cable.

14958

fatwizard
August 28th, 2013, 10:51 AM
You 34 pin cable needs 2 drive connector on it. That's 3 all together. One for the controller and one for each hard drive. Many cable were made for just one drive, since that configuration was more common. If the cable was made for 2 drives, it likely has the twist in it. If not, the the drives must be jumpered as 1 and 2. The twenty pin cable is separate for each drive. If an MFM drive is connected to a different controller than the one used to low level format it, then a new LLF will almost certainly be required.

Bungo Pony
August 28th, 2013, 11:18 AM
Thanks everyone! I had a feeling it would need the twisted cable and I have a few kicking around here.

As a side note, I've been going through all my old computers that I've collected. I've got a PC-XT that someone tried to install Windows 3.0 on. What a great way to waste drive space!

SpidersWeb
August 28th, 2013, 11:57 AM
What controllers do you have, and what drives do you have available?
Unfortunately with this technology it's rarely a case of wire it up and go (like IDE or SCSI usually is).

MikeS
August 28th, 2013, 12:50 PM
Thanks everyone! I had a feeling it would need the twisted cable and I have a few kicking around here.Note that although it looks similar, a hard drive cable with a twist is NOT the same as a floppy cable; different wires are 'twisted'.

And, as Chuck noted above, you do NOT need a twisted cable; if you have a cable without a twist (or a floppy cable with the end connector moved to before the twist) you just need to move the DS jumper on one drive from DS1 to DS0.

geoffm3
August 28th, 2013, 12:55 PM
Note that although it looks similar, a hard drive cable with a twist is NOT the same as a floppy cable; different wires are 'twisted'.

And, as Chuck noted above, you do NOT need a twisted cable; if you have a cable without a twist (or a floppy cable with the end connector moved to before the twist) you just need to move the DS jumper on one drive from DS1 to DS0.

This.

You'll have three cables altogether, one shared control cable as previously mentioned, and two smaller data cables, one for each drive.

Bungo Pony
August 28th, 2013, 01:26 PM
What controllers do you have, and what drives do you have available?
Unfortunately with this technology it's rarely a case of wire it up and go (like IDE or SCSI usually is).

That's what I figured. I'll have to see if any of these drives are identical. With my luck, they probably aren't. I have about 4 hard drives at my disposal, all with controller cards.


Note that although it looks similar, a hard drive cable with a twist is NOT the same as a floppy cable; different wires are 'twisted'.

And, as Chuck noted above, you do NOT need a twisted cable; if you have a cable without a twist (or a floppy cable with the end connector moved to before the twist) you just need to move the DS jumper on one drive from DS1 to DS0.

Thanks for the info. I may have to modify one to get it right.

Bungo Pony
August 28th, 2013, 02:02 PM
Okay, I lied. I have three working hard drives in total. Two of them are ST-225s (yay!) and one of them is made by Miniscribe. The Controllers on the ST-225s are made by Data Technology Corp (BXD07) and the other by NEC (HC-100 Rev C1). The Data Technology one has a n 8-bit dipswitch on it and three jumpers, but the NEC one has nothing.

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I have two other controller cards, one that belonged to a dead ST-225 (Adaptec 400512-00) and a dead ST-251 (WDC) which both have the floppy controllers integrated.

SpidersWeb
August 28th, 2013, 09:03 PM
Well your DTC is already configured for a pair of ST225's - so that was easy! lol I'd use that one.

Once you've sorted the cabling/drive selects you should find the drive that was already on that controller will behave as normal, but for the other one:
- run debug
- type "g=C800:5" (I checked the photo, your card is setup for that address)
- follow on screen instructions

That will low level format the drive so that the controller can use it, then you can use FDISK and FORMAT :) Just make sure it's cabled correctly and you select the right drive (no drama, just annoying when that happens).

modem7
August 29th, 2013, 02:56 AM
The Controllers on the ST-225s are made by Data Technology Corp (BXD07) and the other by NEC (HC-100 Rev C1). The Data Technology one has a n 8-bit dipswitch on it and three jumpers, but the NEC one has nothing.
The Data Technology Corp (DTC) made controller is a model 5150CI. The "BXD07" is the ROM revision level.

The user manual for the HC-100 is at http://www.minuszerodegrees.net/manuals.htm
The HC-100 is a 'dynamic' controller. At low-level format time, it will ask you to enter details of the hard drive/s. Details are in the manual.