Intro to ACCESS.bus (RE: the ACCESS.bus Software Creator's  	Contest Announcement)  WHAT IS ACCESS.bus?  ACCESS.bus is a new open industry standard for computer  peripheral connectivity.  ACCESS.bus is a serial protocol that  uses simple, low-cost I2C technology to link multiple devices to  a single PC port.  Peripheral devices such as keyboards or  keypads, locators (Mice, Trackballs, Joysticks), printers, VR  gloves, digitizers, sensors, actuators or data transmitters and  others can be easily daisy chained to the host PC.  Applications  such as CAD/CAM, Data Acquisition, Simulation, Virtual Reality,  Multiple-Player/Single PC Games, Education and many, many more  can now take advantage of ACCESS.bus, the technology that puts  Plug and Play on every PC.  The ACCESS.bus offers advantages to end-users and developers of  systems and peripherals.  Multiple devices connect to the host  computer with only one port.  Common communication methods for a  number of device types lead to simplified hardware and software  development.  As an open standard, ACCESS.bus enables cross- platform use of the same device.  ACCESS.bus TECHNOLOGICAL DESCRIPTION: =====================================  ACCESS.bus technology is an open specification, enabling anyone  to implement it on host systems or in peripheral devices without  fee or royalty. ACCESS.bus has a bus topology architecture.  That is, a single  host can accommodate up to 125 peripheral devices.  ACCESS.bus  data rate is 100 Kbits/sec.  ACCESS.bus Physical Layer ^^^^^^^^^^^^^^^^^^^^^^^^^ ACCESS.bus is a serial bus architecture, based on I2C hardware  protocol, with one data line and one clock line. Standard low-cost I2C microcontrollers handle bit-level  handshaking, including automatic arbitration and clock  synchronization.    ACCESS.bus Software Protocols ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The ACCESS.bus communication protocol is composed of three  levels: I2C Protocol, Base Protocol, and Application Protocol.  I2C PROTOCOL: This simple and efficient protocol defines  arbitration among contending masters without losing data.  I2C  provides for cooperative synchronization of bus partners with  different clock rates.  Bus transactions include addressing,  framing of bits into bytes, and byte acknowledgment by the  receiver.    BASE PROTOCOL: Establishes the asymmetrical interconnect between  a host computer and multiple peripherals.  The host becomes the  ACCESS.bus manager.  The Base Protocol defines the format of an  ACCESS.bus message envelope, which is an I2C bus transaction with  additional semantics, including checksum. Unique features of the Base Protocol are auto-addressing and hot  plugging.  Auto-addressing assigns devices with unique bus  addresses, without the need for setting jumpers or switches.  Hot  plugging is the ability to attach and detach devices while the  system is running, without rebooting.  APPLICATION PROTOCOL: This is the highest level of the ACCESS.bus  protocol which defines message semantics specific to particular  types of devices.  Each type requires a different Application  Protocol.  Three broad device types have been identified:  keyboards, locators, and text devices.  ACCESS.bus support on the PC ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ All three levels of the ACCESS.bus protocol are supported on the  PC.  An add-on card implements the physical layer and uses the  base protocol to communicate with physical ACCESS.bus devices.   An ACCESS.bus Manager - TSR under DOS and a DLL under Windows 3.1  - controls the operation of the physical layer and interacts with  the ACCESS.bus device drivers.  Drivers are available for  multiple ACCESS.bus keyboards, locators and printers for DOS and  Windows 3.1.  Also available are C language source code examples  of the interface from applications to the device drivers.   To Contact ABIG (the ACCESS.bus Industry Group):