That would be classic then. Classics are available with and without EFIS, therefore that term is somewhat muddled. The NG is only available with an EFIS, which further confuses things.
On the classics the groundspeed readout on the PFD comes from the FMC or IRS with the FMC being the primary source. The mach number comes from the respective air data computer.
The ADCs and IRS units are separate units in the classic models.
Last edited by Denti; 24th Nov 2009 at 08:00.