Burgess Hill, Sussex-based technology specialist Scientific Computers Ltd has one of the most interesting portfolios of fairly obscure scientific computer systems in its armoury, and the company has now become the European distributor for a new range of parallel processing workstations and servers based on the Inmos Transputer. The Cogent Research XTM range (CI No 1,290) is the result of work by Cogent founder Charles Vollum, an Apple Macintosh software developer who liked the idea of providing ultra-high performance desktop computers using familiar environments. The result was the XTM Series, which uses up to 30 T800 Transputers in conjunction with the Linda high level parallel programming language, a new Unix-like operating system called Qix and based around a Linda-like approach, and a windowing system that uses the specification of NeWS from Sun Microsystems. Apart from functions (such as forks) which depend on memory management support, Qix, independent from hardware topologies, is Unix-compliant, and Unix applications are claimed to be convertible with little difficulty. The use of Linda allows for easy development of parallel programs – Linda, invented by David Gelerntner at Yale University, adds four additional commands to languages such as C, C++ and Fortran, which enable data to be transferred between processes and synchronise their execution without specific knowledge of the system architecture. The idea is becoming increasingly popular, with Linda support now offered from companies such as Encore Computer Corp, Sequent Computer Systems Inc and Intel Corp. To complete the picture, Cogent has developed its own Display Postscript- and NeWS-compatible windowing system in C++, and has implemented its own compilers for the Transputer, offering C, C++ Postscript and Fortran. In the XTM, the Transputers all share an ordinary parallel communications bus through which messages and data can be sent. Seperately, the four serial-communications channels from each of the Transputers are connected to an intelligent switch. Inside this, the serial communications from all the Transputers are arranged in a network, but have no permanent connections. On request, the intelligent crossbar switch can directly connect any two Transputers on the network. It takes less than 40 microseconds to establish such a link, and 200 to 400 microseconds to reconfigure the entire computer. The XTM is sold in two configurations: a twoprocessor workstation and a resource server with up to 30 processors, offering a range of performance from 10 to 160 VAX MIPS. The workstation comes with a monochrome or colour monitor, 8Mb RAM, four serial ports, 90Mb to 190Mb hard disk, 3.5 floppy, sound generator, SCSI port, and four Nubus slots. The resource server version has a 16 slot proprietary Lindusbus backplane to accomodate XTM compute or communications boards. The Cogent machine is already selling in the US and Japan, for applications varying from just-in-time scheduling for factories to image processing of satellite data. In Europe, Scientific Computers will target the university, CAD/CAM and military markets. Cogent Research Inc, based up in Beaverton, Oregon, was founded some four years ago.
