PC-100

PC-100 This is 100MHz SDRAM memory in 144-pin SO-DIMM form-factor.

Available memory types from IBM

Partnumber	FRU	Description
20L0253	20L0263	32MB PC100 SDRAM NP SO-DIMM
20L0254	20L0264	64MB PC100 SDRAM NP SO-DIMM
20L0255	20L0265	128MB PC100 SDRAM NP SO-DIMM
33L3069	33L3070	256MB PC100 SDRAM NP SO-DIMM

ThinkPads that support this technology

ThinkPad Models	Soldered on systemboard	DIMM Slot 1	DIMM Slot 2	Official Max-Memory	Unofficial Max-Memory1
390X		Occupied	Empty	512MB2	Unknown
600X	64MB	Occupied	Empty	576MB3	Unknown
A20m, A20p		Occupied	Empty	512MB2	Unknown
A21e		Occupied	Empty	256MB4	Unknown
A21m, A21p		Occupied	Empty	512MB2	Unknown
A22e - Celeron		Occupied	Empty	256MB4	Unknown
A22e - Pentium III		Occupied	Empty	512MB2	Unknown
A22m, A22p		Occupied	Empty	512MB2	Unknown
S30, S31	128MB	Empty	NA	256MB5	Unknown
T20, T21, T22		Occupied	Empty	512MB2	Unknown
TransNote	64MB	Empty	NA	320MB5	Unknown
X20	64MB	Empty or 64MB DIMM	NA	320MB5	Unknown
X21	64 or 128MB	Empty	NA	320MB or 384MB5	Unknown

FOOTNOTES [Δ]

1. See Unofficial_maximum_memory_specs
2. Based on 2x 256MB DIMMs, might require removal of original base memory
3. Based on base 64MB plus 2x 256MB DIMM in Slots 1 and 2
4. Based on 2x 128MB DIMMs, might require removal of original base memory
5. Based on base memory plus 128MB DIMM in Slot 1