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BIOS INT 13h with more than two HDD
Posted: Sat Oct 10, 2015 11:50 am
by tlf30
Hello, I was wondering, will the BIOS ever give values other than 80h & 81h for hard drives, what will it do if you have, lets say, six hard drives?
And if it won't, then how do you use INT 13h to access other hard drives?
Thanks,
Trevor
Re: BIOS INT 13h with more than two HDD
Posted: Sat Oct 10, 2015 1:23 pm
by Octocontrabass
Hard drives are numbered sequentially, starting with 0x80. If there are six hard drives and the BIOS supports accessing all of them through int 0x13, you will see 0x80 through 0x85.
Modern operating systems don't use the BIOS like this, so you may come across systems where some drives can't be accessed using int 0x13.
Re: BIOS INT 13h with more than two HDD
Posted: Sat Oct 10, 2015 8:31 pm
by tlf30
OK, thank you. I am just writing a small program that looks at the different drives attached to the system during boot.