Chip ties PCs at ATM-like speed

Mountain View, Calif. - An interface controller chip from NEC Electronics Inc. promises point-to-point links between personal computers up to 100 meters apart at speeds approaching those of Asynchronous Transfer Mode (ATM) networks. The "Trans Processor" uses loopback signaling technology to transfer data over a parallel cable at sustained rates of 2.5 Mbytes/second.
The chips initial appication wil be in a PC Card 95 card designed to link notebook computers to larger machines, making server data available to the notebook at the speed of the local disc drive
The controller works on an elegantly simple principle. Attaching to a 16-bit parallel cable, the chip sends out a byte of data over one set of eight lines on the cable. It then wwaits for the device on the other end of the cable to echo the data back on the other eight data wires. When correct data arrives, the chip moves on to the next byte.
Since the transfer is effectively self- timed, the chip will adjust to different lengths of cable or different hardware on the recieving end. Ideally, a user would transfer data a short distance between two TransProcessor chips over NEC's propriety, thin 25-wire cable. But NEC has also used the chip to communicate with a standard PC parallel port, employed it with standard ribbon cable and used it at distances up to 100 meters. Those stresses reduce the transfer rate.
The first version of the chip comes with a PC Card 95 interface; the cable interface; and an interface o an optional, 64k x 16 progam ROM. In that form, it drops nicely into a Type 1 PC card, bringing high-speed interconnect and a complete set of file-transport, printer and filesynchronization utilities to a notebook computer in one slot.
Using the card, according to the developers, a notebook computer owner connect to a desktop or file server and have access to the larger machines's disks at the same speed as the local disk in the notebook. Additional applications include connection of high-speed peripherals such as digital cameras.
The current form of the chip is for point-to-point links only. But the developers plan a multidrop version of the TransProcessor soon that would function like a LAN but at a higher speed, without the overhead expense. Such a link would let the small office/home office user interconnect a number of PC's and peripherals without the complexities of network management.
The transfer engine in the TransProcessor was designed by Trans Digital Corp., which will also supply the chip- with flash ROM and software-on a PC Card 95 card for $149 each. NEC will provide the bare chip, which is available now, in a 100-pin thin quad flat pack for $10 each in volumes of 10,000.

Electronic Engineering Times - November 20, 1995.