If you need or want to have multiple operating systems on a PC, you should be able to access them separately. Some operating systems will take over all of the hard drives, and you may lose data or have data corrupted. (This is the voice of experience speaking!) So I came up with a simple fix that involves an external multiposition switch. This is easier than disconnecting the signal ribbon cable and the corresponding power connectors.
Having two distinct operating systems on separate hard drives, I made a two-position double-pole switch operate so that it chooses between operating systems. The figure shows the connection. You can hardwire the drives or use connectors. You can switch as many hard drives as your system has mounted in the PC.
Two voltages are present on the power cable that's connected to each device (floppy drive, hard drive, CD, etc.)—+12 V and +5 V—as well as ground. The ground wires (usually two, colored black) connect to the frame of the PC and each powered device.
While keeping some of the powered devices connected normally (floppy and CD), the multiposition switch permits access to the hard drive or drives in a simple and convenient way. When changing hard drives (operating systems), the PC should be shut down to clear the RAM.
i tried switching hard drives but when i put the old one back, the computer would not boot. any suggestions????? please!
Anonymous -April 01, 2007
Jumpering drives as Cable Select worked. I tried a latch circuit but only PIO mode was reliable. The PC I tried did not like an unpowered Western Digital drive on the cable: UDMA hardware errors occurred intermittently.
Lars White -October 29, 2005 (Article Rating: )
I have been experimenting with the same concept for about a month. Do you have a detailed illustration?
Dennis M. Marshall -August 04, 2005
1. What is done with the data cable? If you have more than one HDD on the same ribbon cable, but one has power off, will the off one pose an odd load and risk corrupting data for the functioning HDD? 2. Will the BIOS get upset to have not been told of the changes? What happens if you have the slave on but the master off?
Peter C. -July 25, 2005
Hi, Theres a better but costly way to do this go to www.industechnologies.com they sell a set up that installs in the front bay areas. This replaced the old romtec kits I now have.This is conveinent way make changing HDS easy. Good luck
KMG -June 25, 2005 (Article Rating: )
We are using this idea for about three month.Works good. For switch we are using toggle switch and latching relay circuit which prevents switching during PC is on. You can toggle the switch any time, but change will take effect only on next powerup. Aleks
ALEKS PINSKIY -March 16, 2005
From many years, i make this manualy but the idea to install a multiposition switch is a very good idea !
Claude Bélanger -March 11, 2005 (Article Rating: )
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