The Epson HX-20: for Business on the Move Considered to be the world's first mobile computer, the HX-20 came from a company better known for its printers (which Epson had been producing for 20 years). The HX-20 was first announced in 1981 but wasn't generally available until 1983 - the year of this advert. The ad also contains an image (on the bottom-right) of its stable-mate, the larger more PC-like (although running CP/M) QX-10. The portable HX-20 would run for up to 50 hours on rechargeable batteries, came with 16kB RAM (upgradeable to 32kB) and even had an optional acoustic-coupler modem available. The display was an LCD capable of displaying 4 rows of 20 characters (a total of 120x32 pixels) and it ran Epson BASIC on two 614kHz Motorola 6801 CPUs. There's more on Wikipedia.