Abstract: A data processing system including a bus (ISA, EISA), in which address lines (SA) and data lines (SD) are connected in parallel to a series of slots for receiving, each, any one of a plurality of available extension cards. Control lines of the bus are connected in parallel to the slots, except at least one specific control line (AEN, SMEMR#) operable to enable a slot by rendering accessible, through the bus, the circuits of a card inserted in the slot. The data processing system further includes means (A, S, 30) programmable through the bus for transmitting the state of the specific control line to predetermined slots.

Abstract: A booting method for a microcomputer consists in executing a Power On Self Test program, loading an operating system and executing at least one current startup file including user-selected programs. The method comprises the steps of (a) storing in a non-volatile register, accessible through a bus of the microcomputer, a programmed time associated with a pending task; (b) detecting the coincidence between the time indicated by a permanently powered clock and the programmed time, and powering-on the microcomputer; and (c) executing, instead of at least one current startup file, at least one startup file associated with the pending task.