An interactive video network between one master computer and a plurality of slave computers

Claim 1

1) An electronic device enabling interactive connection between a master computer and a plurality of slave computers, wherein the master computer comprises a central processing unit (UEo), keyboard (To) and video display unit (Vo) and each slave computer comprises a relative central processing unit (UE1... UE2 ... UEn), keyboard (T1, T2 ... Tn) and video display unit (V1, V2 ... Vn), characterized in that it consists in: at least one master control box (M), comprising, -an independent logic network (LM), linked to the master computer in such a way that the master CPU (UEo) and the master VDU (Vo) are interconnected through the box via a first lead (C1) and a second lead (C2), and the master CPU (UEo) and the master keyboard (To) are interconnected through the box via a third lead (C3) and a fourth lead (C4), and capable of interrupting and restoring connections through the first and second leads (C1, C2) and the third and fourth leads (C3, C4), inhibiting or enabling transmission of the data signals and the synchronizing signals between master keyboard (To) and master CPU (UEo) at one and the same time; -a selector unit (CS) from which to select one only of the plurality of slave computers by way of a relative independent bus (SB) taken from the output of the control box; -a control unit (CC), from which instructions are transmitted through a relative control bus to the logic network (LM) on the one hand, and from the output of the control box (M) on the other; -a set of function buttons (KB, DPR, DPU, MPR, MPU) which operate the control unit (CC) and serve to select the envisaged video and keyboard functions by way of a video bus (VB) and a keyboard bus (TB) respectively, both of which run from the output of the control box (M) and are enabled or inhibited by the logic network (LM) in such a way as to provide video functions whereby a copy of the master screen (Vo) can either be transmitted to the slave VDU (Vi) selected through the selector unit (CS) or broadcast to all of the slave VDUs (V1, V2 ... Vn), and likewise, a copy of the selected slave screen (Vi) can either be relayed to the master VDU (Vo) only or broadcast to the master and all remaining slave VDUs, and to provide keyboard functions, similarly enabled and inhibited by the master logic network (LM) and implemented through the keyboard bus (TB) such that data signals and synchronizing signals are handled at one and the same time, whereby it becomes possible either to retain the connection between each keyboard and the relative CPU, or to enable interaction either between the selected slave keyboard (Ti) and the master CPU (UEo) or between the master keyboard (To) and the selected slave CPU (UEi); a plurality of slave switching circuits (S1, S2 ... Si, Sn) connected in cascade to the master control box (M) via a single multicore cable incorporating the various buses (VB, TB, SB, CB), each linked up to the relative computer utilizing a connection of the type existing between the master control box (M) and the master computer, and comprising, -an independent logic network (LS), incorporating a device (ID) serving to allocate a slave station identity number using the same code as that adopted for the selector unit (CS), which is piloted by the control and selection buses (CB, SB) and holds control over the keyboard bus (TB), inhibiting or enabling transmission of the relative data and synchronizing signals at one and the same time; -a multiple switch device (IC1-2) controlled by the logic network (LS) and installed between the video input bus (VBI) and the relative slave VDU, which cuts directly into the connection with the video bus (VBI).