Category: BIOS
INT 41 - SYSTEM DATA - HARD DISK 0 PARAMETER TABLE ADDRESS [NOT A VECTOR!] Notes: the default parameter table array is located at F000h:E401h in 100% compatible BIOSes; the pointer may be overridden by the hard disk controller's BIOS to support drive formats unknown to the ROM BIOS not used by some PS/2 models BIOSes which support four hard drives may store the parameter tables for drives 81h-83h immediately following the parameter table pointed at by INT 41, with a separate copy of the drive 81h table for INT 46. The check for such an arrangement is to test whether INT 46 points somewhere other than exactly 16 bytes past INT 41, and the sixteen bytes starting at offset 10h from INT 41 are identical to the sixteen bytes pointed at by INT 46 another arrangement for BIOSes which support four IDE drives is to have four tables pointed at by INT 41 in the order primary master, primary slave, secondary master, and secondary slave, in which case (for example) a system with only primary master and secondary master will have valid tables at offsets 00h and 20h, with garbage (but sectors-per-track = 00h) at offsets 10h and 30h SeeAlso: #03196,INT 13/AH=09h,INT 1E,INT 46"HARD DISK 1",INT 60"Adaptec" SeeAlso: INT C0"AMI"