COMMUNICATION APPARATUS FOR TRANSFERRING SIGNALS AND DATA BETWEEN A HOST COMPUTER AND A PLURALITY OF PERIPHERAL DEVICES OVER A COMMUNICATION MEDIUM

摘要

A communications medium for transmitting data between a plurality of peripheral devices and a host computer. Only one device may talk on the bus at a time and only in response to a command from the host. When a peripheral device needs to be serviced, it sends out a service request signal by holding the bus low after any command signal. The device continues to request service until it receives a talk command from the host computer. When more than one device are the same type (for example, two mice) are coupled to the bus, the host computer assigns new addresses to the devices. Devices detect collisions by sensing a low signal on the bus when they attempt to send a "1".