I think there should be a GQ board just for computer questions, so as not to bore the others. In any event…
I’d like to connect a 2nd hard drive, but i don’t want it accessible all the time. It’s usually on standby, so whenever Windows (98) checks for other drives - like when you click “My Computer” - the system has to stop everything and wait for the drive to warm up. Is there a way to turn on a second drive only when i give the O.K.?
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“I think popular music has gone truly weird.” – George Harrison
I think all of the Microsoft OSs automount all of the drives attached to the machine, so, no, I doubt what you want is possible on an MS-Windows box.
But in Linux, you can selectively mount drives, either from the desktop or (the geek option :D) from a command line. When the drive is unmounted, the computer is completely unaware of it. It might as well not be there.
So, if having your computer only aware of a hard drive part of the time is something you want, check out Linux. The various BSDs probably also have that functionality, since Linux and BSD both derive from the same Unix base.
I know you are looking for a software solution but I will open a second front here and you may want to think about it too.
For some years I have been looking at a slightly different problem. I want to disable drives using a mechanical switch. What I want to do is have a computer where I have my drive and another person has theirs and we can each start the computer using our own separate drive. This way there is no risk of viruses spreading, or the other person doing something to wreck my stuff or any privacy concerns.
I believe in the disk flat cable there is one wire which can be interrupted and the computer will not even see the drive. I posted this question some time ago in a computer forum and someone said, “if you interrupt wire #x, the drive is dead, it just sits there like a turnip”. I tried it and it did not work but the discussion continued for a long time in search of what had by now been called “the turnip switch”. Obviously a mechanical switch for all wires is not practical. The other option is one of those removable caddies but I continue my search for the “turnip switch”. Does anyone know how to do this?
I don’t understand how you would interrupt one wire of a ribbon cable without destroying the cable? (I have seen ribbon cables where one wire was worn out/broken, and the BIOS did not see a drive, though.)
Can’t you just put a switch in the drive power cable? If you connect two drives to one IDE connector, set both to Master and only supply power to one of them, I don’t think the other will do any harm.
Or you could use external SCSI drives - I’ve actually seen it done. Connect two drives to the SCSI interface, turn on one drive and turn off the other. True SCSI hard drives are expensive, but there are “fake” external SCSI drives which contain an IDE drive and an IDE-to-SCSI translation chip. I have one made by Mitsubishi connected to a Sun workstation - price was very reasonable and it works well.
tourbot, it is relatively easy to interrupt a single wire of the ribbon cable. At least I’ve done similar things a number of times.
scr4, interrupting the power supply is the first thing that comes to mind. I did all these experiments a couple of years ago and I do not remember the details but I am pretty sure I tried just unplugging the power supply connector and it did not work; at least with the WD drives I was using.
Of course there are other solutions;I have seen the removable trays, etc. but I was looking for the simplest, the “turnip switch”.
Why don’t you put in an IEEE 1394 card (Is that the right designation? You know, FireWire) and use a FireWire hard drive? When you want to use the drive, you attach the FireWire cable.
I’m not sure how, on a PC, you would get it to release the drive when you’re done so you can unplug it, short of shutting down (on the Mac, you drag it to the trash can, a useful albeit unintuitive act that unmounts current mounted drives), but as far as having it accessed only for sessions during which you want it running, the PC would see it when you first added it, autosensing it, right? So you plug it in only when you need it, and then it is on and active for the remainder of your session.
Well, sailor, I saw just what you want at tigerdirect.com It was on sale for $49.00 its a cool little box that fits in your floppy drive bay & it has buttons on the front & you push the button for the HD you want to start it with. Cool, huh? I don’t know how it interfaces with the bios though. Let me know if you can’t find it --its been a few weeks since I saw it there.
You could also do this with an external SCSI drive. Put in a SCSI card if you don’t currently have SCSI, attach external drive. External drive has separate power supply and power switch, so turn it off when not in use. Turn it on as needed (you may need some litle freeware or shareware utility to prod the system into noticing it and mounting it with its driver).
Sailor: If I understand your situation correctly, you’d want two different drives, each bootable, neither of them active and available when the other is booted, right? Easy: Install your operating system onto removable media such as Jaz or Orb (or even Zip, if you can live with a stripped-down OS that fits on a 100 MB disk), the other person does also, then designate that device in your BIOS as your startup device.
Regarding the “turnip switch”, I’d recommend going with the removable caddies. They work well and are fairly inexpensive. I got a deluxe model with built-in cooling fans. The caddy and two drive trays totalled about $50.
You could make up a simpler solution by putting a switch on the power cables but I’d recommend against it. Unless you make a fairly complex switch, there’s always the slight possibility that the drive could be accidentally powered on or off while the machine is running – that would be bad. I wouldn’t even consider trying to alter the ribbon cable.
As I have said, I am well aware of removable caddies and other such solutions but what I am looking for is something much cheaper and simpler: I am not looking for the $50 caddy, I am looking for the 50 cent turnip switch.
Right now I am not sharing my computer, but when I did, I just plugged and unplugged the ribbon cable and power cable. The problem with this is that they are not made for this use and they are easy to damage, especially the ribbon cable.
I just vaguely remember that there is (or used to be) a wire with asignal called something like “drive enable” and you could use it to enable/disable the drive. Put a switch on it and you have the perfect 50 cent turnip switch.
By golly, it was two years ago and I had forgotten all about it but I might try it again. Nothing like the excitement of tinkering with hard drives where you are exposed to lose everything.
Actually under 2k, XP and on up, you can mount or dismount a drive with the Disk Management applet under admin tools. It is also possible to mount a volume UNIX style under a specific directory instead of assigning a drive letter. Now, if MS would only wake up and start supporting soft symbolic links, I’ll be very happy.
Okay, I gotcha. As you said, ribbon cables are fragile. The individual wires within them are also tiny so I recommend against modifying them. Likewise, adding a switch to any one of them opens up the possibility the data path won’t be the same length as that on the other wires, possibly affecting signal sync. If you truly intend to do this, use a switch connected to the power cables of both drives so flipping it toggles between the two. The power cables are more robust physically and electrically than the tiny little ribbon wires.
For the benefit of anyone else who might try this – and it’s probably belaboring the obvious but – do not try to enable or disable drives while the machine is on! This kind of solution does not provide a hot-swap capability.
MalFrog, thanks for the link, that is exactly the idea I am looking for. The switch is expensive but the idea can be implemented with any cheap switch. This idea works by switching just the drive selection jumpers and that is the kind of thing I was looking for. Unfortunately, when I tried it a couple years ago, it didn’t work but I do not remember the details. It was two WD drives (which I still have) and i remember messing with them for quite a while but I never got this to work. I am talking from memory so I may be mistaken but IIRC one of the problems was that the setting for “single drive” was no jumper and setting a jumper on the other drive made it show up as slave or whatever. Maybe I’ll tinker again but I do not know if I want to risk loosing a hard drive…
Handy, my BIOS does the same but that does not make the other drive disappear and so it is vulnerable to viruses, prying eyes and clumsy hands messing all sorts of things. I want my drive to be invisible and unaccessible while the other one is in use.
Just go to the device manager and disable the 2nd drive. Under XP there is no need to reboot (unsure about other OS’s) and the drive is accessible again if you right click and re-enable.
I don’t understand how you would interrupt one wire of a ribbon cable without destroying the cable? (I have seen ribbon cables where one wire was worn out/broken, and the BIOS did not see a drive, though.)