Mains supply control avoiding data loss during mains switch operation - has intelligent mains unit responding to switch operation and signalling personal computer to ensure memory save

摘要

A PC computer system has a CPU (11), keyboard controller (25), peripheral controllers (23, 24) and memories (21, 50, 19). In addition the peripheral controllers connect to a range of devices such as the mouse (34), LED indicators (37) and a loudspeaker (32). A connection is also established with a power supply (44) that has a control microprocessor (44a) and a mains switch status flag (44b). When a mains switch (44c) is operated to turn off the power the flag is set. A communication between the control processor and the PC takes place to ensure that data loss does not occur.