One example is the ITU-T G.hn standard, which provides a way to create a local area network up to 1 Gigabit/s (which is considered high-speed as of 2014) using existing home business and home wiring (including power lines, but also phone lines and coaxial cables). In most cases, the cables are just changed from electrical to optical fiber cables. Mac or Lisa through a small box that is plugged into the serial port and connected via cables to the next computer upstream and downstream. IBM released the IBM Personal Computer in 1981 and included a variant of the Centronics interface- only IBM logo printers (rebranded from Epson) could be used with the IBM PC. After the release of the Apple Lisa computer in January 1983, Apple invested considerable effort in the development of a local area networking (LAN) system for the machines. "If you’re trying to design a system from scratch," he says, "what you probably want is a Danish-type model, what is control cable which relates tax to property values. While a serial port does so with the minimum of pins and wires, it requires the device to buffer up the data as it arrives bit by bit and turn it back into multi-bit values.

Most electrification systems use overhead wires, but third rail is an option up to 1,500 V. Third rail systems almost exclusively use DC distribution. Both overhead wire and third-rail systems usually use the running rails as the return conductor, but some systems use a separate fourth rail for this purpose. 420 V DC, and a top-contact fourth rail is located centrally between the running rails at −210 V DC, which combine to provide a traction voltage of 630 V DC. Power is supplied to moving trains with a (nearly) continuous conductor running along the track that usually takes one of two forms: an overhead line, suspended from poles or towers along the track or from structure or tunnel ceilings, or a third rail mounted at track level and contacted by a sliding "pickup shoe". In Slovakia, there are two narrow-gauge lines in the High Tatras (one a cog railway). Data frames and remote frames are separated from preceding frames by a bit field called interframe space. As well as the rapid expansion of the use of the telegraphs along the railways, they soon spread into the field of mass communication with the instruments being installed in post offices. As well as allowing the construction of a PC-only AppleTalk network, it allowed communication between PCs and Macs with TOPS software installed.

Software handshaking is done for example with ASCII control characters XON/XOFF to control the flow of data. The advantage of software handshaking is that it can be done with absent or incompatible hardware handshaking circuits and cabling. Its disadvantage is that it requires more hardware and cabling, and both ends of the connection must support the hardware handshaking protocol used. If no handshaking is employed, an overrun receiver might simply fail to receive data from the transmitter. It is an example of in-band signaling, where control information is sent over the same channel as its data. Explorer, Aviation. "Fly-By-Wire Aircraft Facts History Pictures and Information". The history of railway electrification dates back to the late 19th century when the first electric tramways were introduced in cities like Berlin, London, and New York City. Today, many countries have extensive electrified railway networks with 375000 km of standard lines in the world, including China, India, Japan, France, Germany, and the United Kingdom.

It was formerly used by the Milwaukee Road from Harlowton, Montana, to Seattle, across the Continental Divide and including extensive branch and loop lines in Montana, and by the Delaware, Lackawanna and Western Railroad (now New Jersey Transit, converted to 25 kV AC) in the United States, and the Kolkata suburban railway (Bardhaman Main Line) in India, before it was converted to 25 kV 50 Hz. However, elastomeric rubber pads placed between the rails and chairs can now solve part of the problem by insulating the running rails from the current return should there be a leakage through the running rails. However, in the early 20th century, alternating current (AC) power systems were developed, which allowed for more efficient power transmission over longer distances. However, Stone left the company in 1899 and the idea was never implemented. Heaviside considered, but rejected, this possibility which left him with the strategy of increasing L as the way to reduce distortion. In the United Kingdom, 1,500 V DC was used in 1954 for the Woodhead trans-Pennine route (now closed); the system used regenerative braking, allowing for transfer of energy between climbing and descending trains on the steep approaches to the tunnel. Approaches for preventing this include reducing the speed of the connection so that the receiver can always keep up, increasing the size of buffers so it can keep up averaged over a longer time, using delays after time-consuming operations (e.g. in termcap) or employing a mechanism to resend data which has not been received correctly (e.g. TCP).