Bitfields for AMD-640 DRAM Type register:
Bit(s)	Description	)
 7-6	reserved
 5-4	type of DRAM in banks 4 and 5
	00 fast page mode (FPM)
	01 extended data out (EDO)
	10 reserved
	11 synchronous DRAM (SDRAM)
 3-2	type of DRAM in banks 2 and 3
 1-0	type of DRAM in banks 0 and 1
SeeAlso: #00983,#00989,#00990