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Switch for HD


GregH's Avatar
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06-30-02, 07:03 AM   #1  
Switch for HD

P2-400, 320megs ram, Win98.
I'm experimenting with a new HD and trying to wean myself of my programmer son's help.
What I'm doing is experimenting with reformatting, partitioning and similar operations.
I have been playing with the new HD and when I need to do something on the computer, I shutdown, replace new with old and reboot to a fully functional HD.
I have been just unplugging the power connector from one and plugging in the other, and it works just fine.
Does anyone know if I could install a double throw switch in the red power wire alone to switch between the two drives?


GregH.........HVAC/R Tech

 
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06-30-02, 11:29 AM   #2  
Nice thought, but it won't work. The glitch: two active partitions at boot (a CMOS and "Windows Registry" configuration issue).

Bottom up solutions:

Software:
1. Fdisk allows, 'requires', selection of the physical drive, by number, when two or more exist. Format syntax requires a drive letter.
1a. Assign the active partition with fdisk. Ask your son to show you how, and maybe write a batch to goof proof he process.
2. Install a third party multi-boot manager. Some provide for fdisk, format, and OS installation.
3. Enable multiple hardware profiles.

Mechanical/Hardware:
4. Install a removable hard drive caddy. One bay for the fixture. Hard drives are attach to a slide tray.
5. Install a drive switch (up to 4 IDE devices on the same channel). Most expensive, uses one bay, but provides drive isolation on the same channel.

 
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07-01-02, 07:14 AM   #3  
2000:
I may not have explained myself clearly.
What I am doing is leaving the ribbon cable to both HD's plugged in and only have one four wire power connector plugged in at a time.
When I want to switch HD's I shut down the computer, unplug the power connector on the current drive, plug in the power connector for the second drive and then reboot the computer. Auto-detect then makes the proper settings and everything works just fine.
The question is: instead of unplugging the power connector each time can the single red wire be switched and would this safely disable the drive.
Couldn't find the link but got the idea from a site that was selling a device like I'm describing. It was just a switch with a couple of connectors that only hooked up to the HD power supply cables.
Didn't look like much, but they didn't show enough to be able to copy.


GregH.........HVAC/R Tech

 
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07-01-02, 01:16 PM   #4  
The hard drive has two power cables, it is supplied with both 5 and 12V. Both have to be disconnected. You could probably get a tandem switch to do the trick.

 
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07-01-02, 01:56 PM   #5  
They make a HD A-B switch that you can install. NOt sure on the price but from what I understand works like a charm. If I can find the link will forward it here.

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07-01-02, 07:27 PM   #6  
Gregh:
I understood clearly enough. trinitro mentioned why your plan would fail. The idea, itself, isn't new or unique. Hard drives and motherboard chips have been fried before with ill conceived home built devices.

Once again, BSB pointed the way: http://www.nicklock.com The nicklock (well designed; with features you wanted), is comparably priced to a removable hard drive caddy.

 
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07-01-02, 09:03 PM   #7  
No, switching the +5v only would work. It's the logic voltage. No +5v, no disk (as far as CMOS is concerned). The +12v is only for the spindle motor.

But having said that, I agree it would be a dangerous way to swap disks. get it dead right, that's ok, get it a little bit wrong, that's just dead ('puter that is).

 
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07-02-02, 07:47 AM   #8  
bigmike
Boot?

Why not just dual boot?

 
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07-02-02, 04:05 PM   #9  
"Why not just dual boot? "

Easy.....Because you can only boot from the master disk. This person requires to boot from EITHER physical drive. That requires that the boot drive be the master drive.

In other words, BOTH drives are jumpered as master - but only one at a time is actually connected.

I repeat, switching +5v would work, but if not done right, "say goodnight Gracie".

(Where was that quote from? - My trivia question for the day)

 
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07-02-02, 05:50 PM   #10  
I get the picture

Where I got the switching idea from was the NickLock site. My memory fudged the details and was mistaken about the power being switched, when in fact they only open the master jumper to disable the drive. From what you are all saying, I take it that switching the power cables would be at some risk.
I guess switching the master jumper would be safer.
My present method of shutting down and switching the power cable to the drives works just fine. A switch would allow me to close up this thing and keep my desk from looking like my workshop.


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07-02-02, 06:55 PM   #11  
bigmike
Why?

Can I ask what you are doing? If you are running two different OS's then the most logical way to go is a dual boot system. I dont understand why you are wanting to do this. Fill me in a little more, tell us what Os's you are running, computer, memory etc.

 
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07-02-02, 08:31 PM   #12  
What I'm up to.

My system: P2-400, 320 megs ram, 5400 rpm 5 gig HD,Win 98 1st edition.
I am in the process of upgrading to a 7200 rpm, 20 gig HD and changing to a different os in the hopes of reducing system crashes.
I have available through my son's employer's user agreement, Win 2000 pro and Win me.
With your assistance I installed Win 2000 last January and had grief with hardware issues, which I mostly sorted out.
After a couple of months of very stable operation Win 2000 crashed.
Win 2000 would not reinstall even with my son's assistance.
Meanwhile I was able to go back to my original 5 gig HD that was on the shelf, reinstall it and be able to get back on the net and have the use of my system as it was before I tried to improve it.
So I now have recently reformatted the 20 gig drive and installed ME. I followed the advice I got last winter and installed my software a little at a time to de-bug everything. Just my luck, I installed Word perfect 8 and when trying to print something I got a Windows error message! After a fresh OS install and only one program............ Go figure.
At my son's suggestion I will reformat, reinstall ME, install my internet stuff and then download the Microsoft updates.
This thing is driving me nuts.


GregH.........HVAC/R Tech

 
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