IBM Corp’s latest ThinkPad Power Series notebooks also offer a choice of AIX, NT and will later on offer OS/2 and Solaris. There are two models, the 820 and 850, both using the 100MHz 603e PowerPC chip, with a choice of 10.4 800 by 600, or 640 by 480 resolution Black Matrix on Array colour screens. The 820 has a 32-bit memory bus, 16Mb memory expandable to 48Mb via memory modules, and a choice of removable 540Mb, 810Mb or 1.2Gb SCSI-2 hard drives, as well as built-in CD-ROM, and two PC Card slots. It weighs 7.3 lbs. The 850 adds a 64-bit memory bus, G10 graphics and up to 96Mb memory, enabling it to handle full-motion video. An optional clip-on video camera turns the machine into a videoconferencing machine. But the the N40 notebook that IBM previously bought in from Tadpole Technology Plc has left the price list.