[mahesh_chavan]

Uptill now I was using IDE hard disk and was able to access using BIOS calls and even LBA 28 direct hardware aceess usng PIO mode without need of any O.S. call.
Now I have purchased new SATA 500 GB hard disk and it is my only hard disk attached to SATA 1 port. My BIOS is showing it as 3rd Master Hard disk and primary and secondary master are absent.
Now I have installed MS DOS 5.0 on first partition which runs okay.
But now I can use only DOS INT 25h TO READ HARD DISK sectors starting from logical sector 0. This means I can not read any hidden sectors including Master Boot Record.
When I use BIOS int 13H calls to read hard disk using drive 80H it does not return any error, but reads nothing. If I use drive 83H it gives drive does not exists error. If I use DOS functions I can access my HDD as drive c ( drive 2) But can not be use to read MBR.
If I shall use MS extension for int 13H I must know the BIOS drive no.
Can anybody tells me how to find drive no. of 3rd Master Harddisk ?
Or which Port I have to use to access HDD using LBA 40 ( 01f0 does not work) in compatibilty mode ?

[modi123_1]

Quote

Now I have installed MS DOS 5.0 on first partition which runs okay.

Woah, wait, what? What do you mean you installed MSDOS 5.0?

[mahesh_chavan]

modi123_1, on 11 September 2014 - 11:22 PM, said:

Quote

Now I have installed MS DOS 5.0 on first partition which runs okay.

Woah, wait, what? What do you mean you installed MSDOS 5.0?

I have running msdos 5.0 in first partition and vista in anoher and ubunntu 12 in third partition
I use MSDOS partition to run old dos applications which occupy very less space and work much faster than any GUI based prgrams complied using sqlite3-free basic and also compile using Harbour Clipper compiler

[modi123_1]

That is certainly a dedication to a product that came out in June 1982 and was over in June 1991 for MSDOS 6.0. Is this some sort of business PC that you are not upgrading the software on? Why would you need to monkey with the interrupts?