T40: CPU is Bannis. Centrino I. Mainboard chipset 855PM. Support DDR266 and DDR333(still working as DDR266). DVD combo 9.5mm is 16X max.ATI 7500 32M. T40P uses ATI R9000 64M. CPU can be upgrade to Dothan 1.8GHz.

T41: adding APS(Active Protecting System). revised 855PM, fully support DDR333. DVD combo 9.5mm is  24X max.ATI 7500,32M. T41P uses ATI R9000 64M. CPU can be upgrade to Dothan 1.8GHz.

T42: adding 15LCD. Dothan CPU. L2 Cache from 1M to 2M. Support DDR333.PCMCIA TYPE II×1＋EXPRESS CARD×1.Support DDR333.T42P uses ATI R9600 64M. adding Bio-Metrix.

T43: adding 15LCD. 915PM/915GM mainboard chipset. SONOMA CPU. CPU can be upgrade to 2.13GHz. Adding Bio-Metrix.
       915GM: GMA900.
       915PM: X300 64M.
       T43P. FireGL V3200 128M. T43P. X600

15LCD T43P is top machine in T4x family! Worthy to own one.