Int 78 Fn 12  - Targa.dev - Send Scsi Command And Data (programmed I/o)    [d]

   AH = 12h
   DS:SI -> command bytes
   ES:BX -> data storage area
   CX = number of data bytes to transfer

Return: AH = SCSI status byte
   CF clear if successful
       AL = SCSI message byte
   CF set on error
       AL = error code (see AH=00h)

Note:  this command sends data internally one byte at a time

See Also: AH=14h

Format of SCSI Command:
Offset Size    Description
 00h   BYTE    length of command
 01h   ??? command bytes