Power-conservation system for computer peripherals

A system for conserving power consumed by a device designed to receive host data from a host, said system comprising:

• a power switch for turning on and shutting down said device, said power switch being coupled to said device for controlling the supply of power thereto, said power switch turning on said device in response to an on command, said power switch turning off said device in response to an off command;
• a data handler for handling data activity, said data activity including receiving said host data from said host, and said data activity including transmitting said host data to said device, said data handler including
• ready indicator means for receiving a ready signal from said device after a most recent on command and for determining when said device is ready to accept data, and
• an emulator for, after a most recent on command but before said device is ready to accept data, transmitting emulator data to said host that corresponds to device data that could have been transmitted by said device if a most recent off command had not been issued;
• and
• a controller for controlling said power switch, said controller being coupled to said data handler for determining whether data activity is present, said controller including a timer for determining in response to said determination of data activity when a time-out interval of data inactivity has elapsed, said controller being coupled to said power switch for sending said on and off commands thereto, where
• said controller sends said on command when, while said device is off, data activity is detected, and
• said controller sends an off command when, while said device is on, said time-out interval of data inactivity has elapsed.