two hard disks

Hello guys, I have two hard disks, both have separate operating systems. I have to attach and deattach both hard disks with the system to use other operating system, Is there a way that I don't have to do this, just use 1 hard disk that I want without deattaching other.
For detail
I attach both hard disk with my system, If I want to use 1 hard disk, other hard disk should not be available, so if I use 2nd hard disk 1st should be unavailable.

 

Connect them both, being sure that the jumpers are correct.

Download GAG Boot Manager, follow the directions to create a floppy, boot from the floppy and install it.

It does not require or use any information about what partition is "active" so you don't need to set up any of that or have any active partitions at all.

Then, set up the boot manager and you will be able to choose at boot which OS you want to use.

There are options in GAG to hide the operating systems from one another, if you choose or if there are any problems that result from their being accessible to one another.

http://gag.sourceforge.net

 

thanks, i check it

 

If your bios permits, you can also choose which hard drive to boot from there too

 

thanks both, I am not very advance in assembly language, I think that there should not be any loss of data.