BIOS / Int / Int 13 / 0F

              INT 13 - FIXED DISK - WRITE SECTOR BUFFER (XT,PS)

Input		Output
AX	0Fh	Status	AX
BX			BX
CX			CX
DX			DX
ES:DI		Set if Error	CF

Status: See function 01h

Note:   Should be called before  formatting  to  initialize the controller's
        sector buffer. Used for diagnostics  only on PS/2 systems.