The Atari Portfolio (Atari PC Folio) is an IBM PC-compatible palmtop PC, released by Atari Corporation in June 1989. This makes it the world's first palmtop computer. History DIP Research Ltd. based in Guildford, Surrey, UK released a product in the UK called the DIP Pocket PC in 1989. Soon after its release, DIP licensed this product to Atari for sale as the Portfolio in the UK and US. In Italy, Spain and Germany, it was originally marketed as PC Folio instead. DIP officially stood for "Distributed Information Processing", although secretly it actually stood for "David, Ian and Peter", the three founding members of the company who were former employees of Psion. The original founder of the company (first called "Crushproof Software") was Ian H. S. Cullimore, and the other two David Frodsham and Peter Baldwin. Cullimore was involved in designing the early Organiser products at Psion before the DIP Pocket PC project. The technologic successor of the Portfolio was the also DIP-developed Sharp PC-3000/3100. DIP Research was later acquired by Phoenix Technologies in 1994. Technology The Portfolio uses an Intel 80C88 CPU running at 4.9152 MHz and runs "DIP Operating System 2.11" (DIP DOS), an operating system mostly compatible to MS-DOS 2.11, but with some DOS 2.xx functionality lacking and some internal data structures more compatible with DOS 3.xx. It has 128 KB of RAM and 256 KB of ROM which contains the OS and built-in applications. The on-board RAM is divided between system memory and local storage (the C: drive). The LCD is monochrome without backlight and has pixels or 40 characters × 8 lines. The sound is handled by a small Dual-Tone Multi-Frequency speaker capable of outputting tones between 622 and 2,489Hz, the same range as touch tone telephones, so users could not only use the address book app to store phone numbers, but actually speed dial them too by holding the device up to a telephone handset. Power is supplied by three AA size removable alkaline batteries. The computer's memory is preserved during battery changes. There is also an optional AC adapter (120V: HPC-401, 230V: HPC-402). There is an expansion port on the right side of the computer for parallel (HPC-101), serial (HPC-102), modem or MIDI expansion modules. It uses a Bee Card expansion port for removable memory (aka Credit Card Memory or CCM), which is not compatible with PC card as it predated that standard.