OFF       : 0
EEPROM 4k : 1
EEPROM 16k: 2
SRAM      : 3
SRAM 768  : 4
FLASHRAM  : 5
ROM ID or CRC HI can be used for game detection. (check "ROM Info" menu for details)
Two samples below
-----------------------------------
N6=1 (Dr. Mario. ROM ID detection)
0xce84793d=3 (Donkey Kong [f2]. CRC detection)
0xce84793d=3 	(Donkey Kong [f2]. CRC detection)
0x1F95CAAA=3	(Donkey Kong 64 (E) [f1] Boot&Save)
OS=1 		(64 Oozumou)
O2=1 		(64 Oozumou 2)
0x96BA4EFB=3 	(Derby Stallion 64 Beta)
0x19E0E54C=1	(Dragon King)
GL=1 		(Getter Love!!)
0x25414DCA=1 	(Glover Prototype)
JG=3 		(Jinsei Game 64)
SB=1 		(King Hill 64 Extreme Snowboarding)
0x0D93BA11=2	(Kirby 64 - The Crystal Shards (E) [!])
0x46039FB4=2	(Kirby 64 - The Crystal Shards (U) [!])
0x21548CA9=3 	(Mini Racers Prototype)
PM=1		(Premier Manager 64)
PT=1		(Puyo Puyo 4 Puyo Puyo Party)
R7=2		(Robot Ponkotsu 64 7tsu no Umi no Caramel)
IB=3		(Shigesato Itoi's No. 1 Bass Fishing! Definitive Edition)
T3=2		(Shin Nihon Pro Wrestling Toukon Road 2)
0xBC9B2CC3=5	(Starcraft 64 Prototype)
0xFD6907F0=5	(Starcraft 64 German Prototype)
0xD52FE29D=1	(Donchan Puzzle)
0x6D9D1FE4=1	(Eleven Beat: World Tournament)
0x4248BA87=1	(Kuru Kuru Fever)
0x315C7466=1	(Star Soldier: Vanishing Earth Arcade)
0x90AF8D2C=1	(Tower & Shaft)
0x2F57C9F7=1	(Vivid Dolls)
0xB73AB6F6=1   (Sin and Punishment - English Translation)
TX=1      (Taz Express)
0x7f43e701=1   (Top Gear Rally PAL)
GF=1
0x5D40ED2C=1	(Viewpoint2064)