Amstrad introduced the PPC-640 in 1988 as a low-cost IBM-compatible portable. It weighed 22lbs. It ran on ten C batteries or mains power and offered a 320x200 flip-up monochrome screen. The CPU was an Intel 8088, clocked at 4.77 MHz. It came with a "full" 640K of memory and included a 2400 bps modem.