Holding down the <INSert> key while booting prints a detailed BIOS ID 
at the bottom of the POST screen, as follows: 

 51-0421-001437-00101111-071595-M571-007_66_M571-H 
 000-0-0000-00-00-0000-00-00-000 
 000-0-0000-00-00-0000-00-00-00-0-000000003FC91010 INT13-1.2 
 Cr-6.26.00 CPU-3.03 DIM-1.80 GPC-1.11 APM1.2-1.11 USB-1.02 IO-1.09

GPC = Green PC

APM = Advanced Power Management, a legacy technology in personal computers
 http://en.wikipedia.org/wiki/Advanced_Power_Management

INT13 = BIOS code for Low Level Disk Services
 http://en.wikipedia.org/wiki/INT13

Cr = BIOS Version : 0626,  AMIBIOS 062600

DIM = Device Initialization Manager
The DIM gets control at various times during BIOS POST to initialize different system busses.