Hand-held computer (HPC)

Hand-held computer (HPC) of the main functions include: operation processing, data storage, input and output, data communications and system expansion in five areas, the organic combination of hardware and software is the full realization of the necessary conditions for these functions. In the operating system using Microsoft's Windows CE2.0 under the premise of the selected hardware system design has some limitations, must support this operating system. In addition, the hardware must meet the requirements of Chinese information processing. Because it is hand-held computer, the machine size, power consumption and ergonomic requirements, etc. should be given special consideration on.The key technology in HPCProcessing operationsRunning Windows CE requires a specific series of 32-bit processors, in addition to basic information processing functions, such as personal information management (PIM), calculators, electronic dictionaries, maps, database search and graphical user interface needs, but also requires a digital communications as , handwriting recognition, artificial intelligence, language input such as high information processing demands of computing power. For example, V.34 Modem about HPC softwareTake 15MIPS (million instructions / second) computing, voice compression required 20MIPS calculations. Processor designed for embedded applications by the chip size and power consumption constraints, the use of reduced instruction set architecture (RISC), not only simplifies the structure of the chip, while the chip's performance has been greatly improved. Hitachi SH4 processor recently introduced frequency reached 200MHz, computing speed of 360MIPS. Currently, for the HPC 32-bit RISC processor the vast majority of Hitachi SH3 or MIPS Technologies, Inc. (now acquired by SGI) of the R3000 core chips (such as the Philips PR31700, NEC's VR4101, etc.), even though Windows CE 2.0 version supports Intel's x86, Motorola's PowerPC and DEC's ARM processor, but a very small share of the market, the lack of a wealth of commercial software.Data StorageSince there is no hard drive as an external memory HPC, all software and data on the memory, RAM and ROM capacity of greater demand. Windows CE 2.0 is the minimum configuration 2MB RAM and 4MB ROM; Chinese Windows CE came out, the ROM will be a greater need, such as the development of the Chinese because of his own information input and output procedures, at least 8Mb capacity of the ROM. Mask ROM and Flash Memory (flash memory) is the two options, the former large-scale production cost is low, which can be updated online. Intel uses an innovative multi-bit memory cell technology to produce a single 64 megabit (Mbit) Flash memory, the United States, AMD and Toshiba of Japan have also produced a suitable battery-powered 32Mbit of Flash chips.OHPC's input in the form of pen (Stylus), voice, keys and keyboard. In the pressure-sensitive pen touch screen (Touchscreen) carried on, as the most important input in the form. There are two ways to use voice input the purpose, one for voice recording, and the other is the use of voice identification, as a text or command input. Key was set up to a key access to information, to facilitate the use of non-professional users. The keyboard is a traditional computer input devices, especially for text input type foreign letters, but also the professional desktop user accustomed to the entry form. With the palm of the HPC and the growing maturity of online character recognition, this input is not indispensable, and there may be pen and virtual (software) keyboard replaced. HPC's LCD display and voice output with two, corresponding to human visual and auditory. Screen size is 1 / 2 VGA of 640 × 240 matrix and 1 / 4 VGA dot matrix of 240 × 320, displays the GUI environment of text and graphics data. LCD with monochrome, grayscale and color of three, from low to high price, monochrome LCD common 2-bit 4-level grayscale, color LCD is 8-bit 256 most colors. Voice output can not only playback of audio input signal, but also synthesized voice output by the text, proofreading and language learning to provide voice capabilities. In addition, auto-tone dialing, voice output alarm clock time is also prompted to complete the basic application.Data communicationFlexible and powerful communications capabilities make up a small box on the HPC machine limitations, data synchronization with desktop PC update is different from the previous HPC significant feature of the PDA. Uses the RS232 standard serial and IrDA infrared interface can be achieved between the HPC and HPC with local PC contact synchronization and data exchange to be completed and the program is loaded with upgrades. Remote computers with Internet and E-communications and Pocket PCmail transmission based on a 33.6kbps, based on the V.34 Modem, after all, analog telephone lines or the most popular communications infrastructure. Modem channel decoding and error correction can be calculated by the main processor through software, the system only plus a V.34 analog front-end interface chip can be eliminated based on the PCMCIA Modem previously used too much current (about 600mA) problems. In addition, infrared can also configure the adaptive function, the implementation of a variety of different remote control appliances.