Abstract: An interface unit, intervening in the high-speed transfer of data between an associated peripheral unit and a central memory of a processor, comprises a first and a second binary counter CM.sub.1, CM.sub.2 for the respective storage of memory addresses and of the number of data words to be read out from or written into a series of such addresses. In response to the arrival of an input/output instruction from a program memory of the processor, intended for the associated peripheral unit, a first sequential network RS' controls the loading of these counters with a starting address and an initial word count; if no other peripheral unit takes precedence, a second sequential network RS" then causes transmission of the contents of the first counter CM.sub.1, during successive cycles of a microroutine established by a control unit of the processor, to that processor followed by the readout (or write-in) of data words at the corresponding addresses, with incrementation of the address in counter CM.sub.

Abstract: To facilitate the insertion of printed-circuit boards into a holder whose sidewalls form guide tracks for these boards and whose bottom has contacts engageable by terminal tabs on the boards, as well as the extraction of such boards from the holder, a C-frame adapted to span the holder surrounds a slider having a pair of lugs which point to the interior of the holder when the frame legs come to rest on its sidewalls and which carry hooks fitting into holes of a printed-circuit board lying in the plane of the frame. The slider is biased by leaf springs into an extended position, defined by stops on the frame legs, in which it can be locked by a latch during an insertion operation. For extracting an inserted printed-circuit board from the holder, the slider is unlocked and is then squeezed against the ridge of the frame resting against the holder walls to disengage the terminal tabs from their contacts before fully withdrawing the board.

Abstract: A marker controlling the establishment of connections between local subscriber lines and inter-office links, via an associated line concentrator/distributor, comprises a link allocator, a signalization unit and a service unit. The link allocator responds to requests from a local subscriber line, transmitted via a line finder, or from a remote exchange, arriving over a common signal path, to control the line concentrator/distributor for connecting that local line to an available link or a designated link to a selected line. The signalization unit coacts with a respective two-way coupler in each link, in a time-division mode, to pick up outgoing dial pulses for transmission via the common path and to transmit switching instructions from that path to the engaged subscriber line. The service unit, communicating with both the link allocator and the signalization unit, receives and sends out information relating to possible malfunctions or alarm conditions.

Abstract: In order to convert a basic frequency by an odd integer K = 2n.+-.1, a square wave of that basic frequency is fed alternately over a noninverting and an inverting branch of a switching circuit to a pulse counter working into a decoder which emits a resetting pulse for the counter on every n.sup.th cycle. A flip-flop alternately set and reset by successive setting pulses feeds back a control signal to the switching circuit for a periodic reversal of the polarity of the incoming square wave either in the middle of the n.sup.th cycle, for K = 2n-1, or after a half-cycle delay from the end of the n.sup.th cycle, for K = 2n+1.

Abstract: A conductive sheet-metal clip, to be soldered onto a chip of integrated circuitry, has two prongs interconnected at a base which forms a seat for an edge of the chip fitted between these prongs, one prong being rigid while the other is weakened near the base so as to be resiliently deformable in the plane of the clip. One prong has a pair of projections engaging the chip at two points, near its free end and near the base, whereas the other prong has a projection bearing upon the chip at a point about midway between the first two points. A terminal tab extends from the base in the region of the rigid prong.