INT 2F - CD-ROM - ABSOLUTE DISK READ
AX = 1508h
ES:BX -> buffer
CX = drive number (0=A:)
SI:DI = starting sector number
DX = number of sectors to read
Return: CF set on error
AL = error code (15=invalid drive,21=not ready)
CF clear if successful

See also: 2F1509

2F1508 - CD-ROM - ABSOLUTE DISK READ