INTRODUCTION
For achieving this the Simputer project was conceived during the organization of the Global Village, an International Seminar on Information Technology for Developing Countries, conducted during Bangalore IT.com event in October 1998.[1]
If the right service is made accessible in the right way information technology can impact the lives of the people all over the world .The Simputer is a low cost portable alternative to PCs, by which the benefits of IT can reach the common man. It has a special role in the third world because it ensures that knowledge of English is no longer a barrier to handling a computer. [1]
Simputer’s About:
Ø Bridging the Great Digital Divide
Ø Affordable Computing: A device which can bring benefits of IT to the people[7]
The key to bridging the digital divide is to have shared devices that permit truly simple and natural user interfaces based on sight, touch and audio. It is designed to be modular and extensible and based entirely on free software from the open source initiative.
Developers
Simputer was developed indigenously by scientists from the Indian Institute of Science and technologists of Encore Software. They have started a commercial venture, PicoPeta Simputers Pvt. Ltd., to ensure that it does not, like many other promising projects, remain on the drawing board. The Simputer Trust is a non-profit trust created basically to develop technology that will help take information technology to rural areas. The Managing Trustee of the simputer trust is Mr.Vinay Deshpande. The other trustees are Vijay Chandru (IISc), Shashank Garg (Encore), Vivek.K.S (IISc), Swami Manohar (IISc), Mark Mathias (Encore), and V Vinay (IISc). Rahul Matthan (Trilegal) is the legal counsel for the Simputer Trust and has played a key role in defining the Simputer General Purpose License.
Affordable Computing
The projected cost of the Simputer is about Rs 9000 at large volumes. It uses all off-the-shelf components so they are mature technology components that do not have a very high price.[4]
Simputer Vs Palm
Simputer is not a PDA, it is a lot more powerful than a typical PDA; it has a 206 MHz RISC processor. The screen size is 320x240, with memory of 32 MB RAM. It is a complete Linux machine, it runs x-windows; we can run many x-applications by simply recompiling for the ARM processor. We have xterm and xclock running on the prototypes of the Simputer. [7]
Similar devices
The designs similar to the simputer are: the Japanese Morphy One, the Pengachu and more recently the Brazilian 'VolksComputer'.[1]
SIMPUTER ARCHITECTURE
Hardware
| CPU | Intel's StrongARM SA-1110 CPU running at 206 MHz |
| Memory | 16-64 MB of SDRAM |
| Display Options | 240x320 LCD Colour or Monochrome Display Panel with backlight |
| Input Device | Touch-panel Overlay on LCD Display with a plastic stylus (Pen) |
| Audio Interface | Audio Codec |
| SmartCard Interface | SmartCard Reader/Writer |
| USB Interface | |
| | |
| Connectors in Basic Unit | SmartCard Connector |
| Power Supply | 2xAA-sized NiMH batteries |
System Software | |
| Operating System Soft-Modem Algorithms Network Protocols Perl/Tk scripting environment | Linux Kernel 2.4.18 V.34/V.17 Data/Fax Modem Technology TCP/IP, FTP, Telnet, PPP, HTTP etc. |
Application Software
Accessories
Expansion Docking Cradle
Compact Flash [CF-II] Slot, USB Slave and
Development Tools
Software Development Kit [SDK] consisting of
q ARM Cross-compilation Tool-chain
q Utilities[8]
HARDWARE
Smartcard interface
Smartcard driver for the simputer is a driver for the Philips TDA8008 smartcard controller. It uses the ALPAR protocol to communicate with the controller. The controller supports ISO7816-4 complaint cards following the T=0 and T=1 protocol. Drivers are available for Linux/x86, for use with the smartcard development board and for Linux/arm, for use with the simputer.
The Smartcard driver for the Linux/x86, uses the serial port to communicate with the development board. In the case of the arm platform, the driver uses a kernel module to communicate with the controller. This is because a polling serial driver is used rather than the default interrupt-mode serial driver in Linux. Currently, the smartcards that have been tested include BULL-CP8, Schlumberger Payflex and Philips DS Personalization cards. [2]
SYSTEM SOFTWARE
The boot loader : Blob
The boot loader used on the simputer is called blob. Blob for the simputer is present at offset 0 on the flash of the simputer, and is responsible for loading the kernel and ramdisk images from flash to DRAM. It also displays a logo on the LCD of the simputer when it is loading the kernel and ramdisk. This logo is also stored on the flash and can be replaced by our favourite logo too.[1]
The Simputer Linux kernel
The Linux kernel for the Simputer is based on the arm patches to the Linux kernel maintained by Russel King and Nicolas Pitre. This has been modified to work on the Simputer. The current kernel version is 2.4. The source code includes the drivers for flash, audio , keypad on the simputer, and simputer touch screen and frame buffer.[1]
The Ramdisk image
The Ramdisk image is transferred to DRAM by blob, during boot time, and is used by the kernel as a root file system on ramdisk. It contains the GNU C library and associated libraries, a shell, busybox, various startup scripts and a flash driver to mount the flash file system. The Ramdisk image is a compressed ext2 file system created using the loopback file system.[1]
The flash file system
The flash file system on the simputer contains libraries required for XFree86 clients (libX11, libXaw, libXt...), Perl 5.5, Perl/Tk, perl modules required for IMLI (XML::Parser, MIME::Base64), rxvt, xclock, chimera, Tapatap, wmx, kernel drivers for the simputer, all compiled for the arm. The flash file system is an ext2 file system. It also includes various X11 fonts that are required by the applications.[1]
Modifications to X-Windows and Window Manager
Modifications to XFree86 4.0.1
X window gives some X windows related developments including the modified wmx window manager used on the Simputer and the patch to X needed for portrait mode 4-bit display. XFree86 4.0.1 runs in portrait mode (required by most handhelds), for displays whose depths are 8, 16, 24 and 32 bits.[1]
Modifications to the window manager (wmx)
wmx-5 requires clicks from both the mouse-buttons and some keyboard clicks for effective usage. Since the right mouse click is not easy on a touch screen, and since the simputer does not have a keyboard, modifications have been done for easy usage on the simputer. A launch menu has also been added. The modified wmx follows the same licensing model as wmx.[1]
The Simputer Softmodem
The modem for the Simputer has been written in software and currently works at 2400 bps without error correction. The code currently is capable of uploading a file from the Simputer to the remote host and has been implemented in user level.[1]
The softmodem distribution includes the following files:
1. A user level V22 softmodem (2400 bps)
2. A driver for the telecom codec (ucb1300)
3. Userland utilities for controlling the telecom codec like going off/on hook, changing sampling rates, buffer sizes etc.
SIMPUTER SOFTWARE PACKAGES
IMLI: The IML browser
IMLI is an abbreviation for IML interface. The purpose of IMLI is to provide a simple and consistent interface for displaying information and developing applications that are simple, user friendly. IMLI supports display of Indian languages, and is also integrated with a speech-synthesis system, that is capable of synthesizing voice in Indian languages. The speech synthesis system is distributed separately. It uses a protocol called ITP, IML transport protocol.[1]
The novelty of the Information Markup language (IML) browser (user-interface of the simputer) is:
Ø uniformity across diverse applications
Ø ease of use
Ø support for multilingual text and speech output
Ø support for smart card usage.
Tapatap: cool character composition
Tapatap is a method for generating keystrokes to be sent to other applications, for devices, where a keyboard is absent. Tapatap uses a 3x3 grid for recognizing characters. For example, each character of the Kannada alphabet can be generated by "tapping" on the cells of the 3x3 grid in a particular sequence. The figure generated by connecting the "tapped" points, roughly resembles the way the character is written. Tapatap starts of in "letter" mode; it can be changed to go into "number" mode by clicking on the button at the bottom. This brings up the numeric telephone style keypad, for number entry. Clicking again on the button at the bottom, brings it back to the "letter" mode. [1]
DHVANI: The Simputer Text-to-Speech Software
DHVANI gives resources needed to set up text-to-speech synthesis in Indian languages. Using images in conjunction with voice output in local languages makes the Simputer accessible to a larger fraction of the Indian population. Currently, Dhvani has a Phonetics-to-Speech engine which is capable of generating intelligible speech from a suitable phonetic description in any Indian Language. In addition, it is capable of converting UTF-8 text in Hindi or Kannada to this phonetic description, and then speaking it out using the Phonetics-to-Speech engine.[2]
Technical Description
Text to Phonetics routine
The Text-to-Phonetics routine for Kannada/Hindi reads a text in UTF-8 format and converts this text into phonetic description. Indian Languages are, by and large, phonetic in nature, so this task does not present major challenges. Hindi, however, turns out to be an exception. Eg:why is karna, i.e. to do, pronounced karna and not karana? The Hindi routine uses a new algorithm to determine where this implicit vowel occurs; this algorithm works correctly for all basic words but goes wrong on compound words, like DevNagar ,which it would pronounce as Devangar. Kannada poses no such problems and is relatively straightforward. Sample UTF-8 files for Hindi, Kannada, and phonetic demo files for Hindi, Kannada, Tamil and Malayalam are included with the distribution. [1]
Phonetics-to-Speech Engine
The Phonetics-to-Speech Engine works by diphone-concatenation. It uses a database of about 800 basic sounds, which are pitch-marked. All the engine does is to read the phonetic description, identify the appropriate diphones, concatenate them at pitch-marks, and play out the resulting signal. To reduce the database size, we use an open-source implementation of the GSM 06.10 RPELTP compression standard. This reduces the database size to about1MB (even though it appears to be 2MB due to fragmentation).All basic sounds are recorded at 16000Hz as 16 bit samples.[1]
INFORMATION MARKUP LANGUAGE (IML) 0.8
Abstract
IML is an XML (Extensible Markup Language) application so it follows the Internet standards.It is used for describing the content and applications handled by a Simputer. The goal of IML is to enable handheld computers, that have limitations in the display size and input capabilities, to access and render content from the Internet. Use of simple icons to be selected by pointing with a stylus and text-to-speech output in the local language are the two primary means of communication. The user is not expected to be familiar with the currently widespread user interface paradigm -windows, slidebars and pull-down menus. [1].
IML Encoding
All application data is transferred between IML applications in a simple self-extracting format called IML encoding. The underlying assumption is that all data is in the form of a simple three column table. It can contain an arbitrary string, including characters that may have special meaning to XML, or to the IML encoding scheme itself. The following example illustrates this coding scheme:
Name Magic Value----------------------------name s Manoharaddress s CSA Department, ISRO, Bangalore DOB s June 21 1960 Status e567rty Marriedphone ru87iii89 3092368choice t345tyu pizza--------------------------------- The table has six rows and 3 columns.
The IML encoding of the above table will be a single long string as shown below.
S[6,3:4:Name1:s10:S. Manohar7:address1:s38:CSA Department, ISRO,
The general format of the string is as follows: start with an 'S[' followed by the number of rows and the number of columns in the table, separated by a comma. The ':' (colon) is used as a separator between the contents of each cell in the table. For example, in the encoded string above, after the initial "S[6,3:", (indicating a table with six rows and three columns) 4:Name indicates that the next 4 characters are to be read as a key, followed by a single character ('s' for secure variable), followed by a 10 character string which is the value for the key just encountered. [1]
IML Overview
The basic unit of an IML document is a page . An IML document can be thought of as a deck of pages. A page contains three types of elements:
Immediate Content: These elements are a small subset of the content markup present in HTML. Since the display of a Simputer is much smaller than desktops, the range of features displayed is limited. For instance, frames are not very meaningful. Some elements in this category are text, table, itemized text, image, audio etc.
Generated Content: These are elements useful in generating content either by applications running locally or by remote applications. Some elements in this category are appl, input, output, select etc.
Control elements : These elements control the rendering of the other elements. Some elements in this category are iml, head, b, i, u, large, small, lang etc.
IML Syntax
IML syntax is governed by the rules of XML syntax and its grammar is specified by a Document Type Definition (DTD): the details of using tags, attributes, entity references and so on are defined in the XML language specification and the details about IML element, attribute names and their nesting etc. are specified in the IML DTD.
Description:
Element for holding the title of the document.
Example of title can be seen in various IML examples presented in this document.
Description:
This is the root element of an IML document and holds all its content.
Attributes of : None.
-- Header Information element
Description:
Currenlty the head element simply contains a title element. Subsequent versions of IML will include elements for author information and other meta information about the document.
Attributes of : No attributes.
Description:
For presenting text content.
The text element is distinct from text directly occuring inside a page element in that its attributes enable pieces of text to be hyperlinked. Otherwise, the presentation of text in this element can be modifed by the use of b, i, u, small and large elements.
This element provides a simple listing environment. The attribute style controls whether it is a numbered list or a bulletized list. A list element can contain most of the other elements.
Attributes of : style = enum|bullet
-- Image display element
Description:
The image element unlike its HTML counterpart, is quite complex and allows for interesting image presentation and manipulation. IML images have the notion of a canvas on which the pixels are rendered. Several images can be placed on this canvas and moved around on the canvas. Since this is an empty element, the various values of the attribute control the effect of the image element.
Attributes of :
The following is the list of attributes:
id: attribute identifies each image entity and is useful in image manipulation, both by subsequent image elements as well as by the update element (discussed later).
mode: attribute can have one of three possible. values create|src|draw.
When mode=create, the width and height attributes specify the size in pixels, of the canvas on which subsequent images can be placed.
When mode=src, the image file (only gif format is supported) specified by the src attribute is placed on the canvas created by an earlier image element, identified by the tagid attribute.
The xoff and yoff elements can be used to specifiy the offset from the origin of the canvas at which the image is to be placed.
When mode=draw, it is possible to specify line and arc drawing using the draw, coord, extent, fill attributes. The config attribute can be used to scale or move the images placed on the canvas by preceding image elements.
audioformat, audio, audiomode and speak: These attributes are valid only when mode=src, and they allow audio content to be associated with an image. Look at the semantics of the tag for more information.
<setattr>
Description:Changing various attributes of elements
<input> -- Input element
Description: The input element is the basic element for obtaining user input, primarily in forms.
Attributes:
There are several attributes to the input element. these are
type: text|password|check|radio|
width: width of the text area
height: height of the input text area
var: name to be asociated with this input field
magic: one of r|e|s|t (respectively, read, exclusive,secure and transient)
value: value of the variable
The var attribute has an important role in enabling IML to deal with smartcards. The var attribute can take any alphanumeric string as its value with a special case of a name starting with the underscore('_') having a special significance. See IML and smart card for details.
For a variable name starting with an underscore, the value of the variable is to be obtained from the smartcard, using the appropriate passwords input by the user. The level of security and access is defined by the magic attribute as follows:
magic=r : The variable is readable by anyone without a password. For changing thatvariable, a password is required. magic=e: The variable is readable and writable with passwords. magic=s: The variable is secure. It is readbale with a password, but cannot bechanged from the IML environment.magic=t: The variable is transient and can be accessed using a password, buthas no permanence beyond the current session. (i.e. the value is not stored on the smartcard)
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